Nothing Special's '71 Bronco

[Gary Lewis]

On the recommendation of some people on the Bronco forum I got this insulating gasket. The first issue I had was that my mounting studs weren't long enough for the added thickness (~3/8"). I had some 5/16-18 ready-rod so I made new studs (maybe I'll get real studs for it some time).

Next issue I had was that I believed the website that called it a gasket. It didn't feel like a gasket to me, and I doubted it's ability to seal. But I put it between the carb and manifold anyway and started it up.

Spraying carb cleaner around the base of the carb showed a whole lotta vacuum leaks. Fortunately I had a couple of stock gaskets. So I put one on either side of the new "gasket" (more of a spacer really) and tried again. No leaks this time!

It's definitely better now, but not perfect. I stopped for gas (engine definitely up to temp) and when I restarted it took quite a bit of cranking, but did start without my needing to hold the throttle open. (This was running on the aux tank that was empty over the winter and filled a few weeks ago. So it was fresh-ish regular 87 octane E10)

At the gas station I filled it with non-oxy premium and switched to the main tank (which had been empty), so the next test was with fresh non-oxy. Again with a hot engine I leet it heat soak while I ran in to NAPA to get pads and rotors for my son's car. And again it started without holding the throttle open, but with a lot of cranking.

So like I said, better but not perfect. I'll live with it like this for the foreseeable future. And I now know that there's no point in chasing down the much more expensive non-oxy fuel.

Well, as Jim says, progress is good!

So it is pretty sure to be heat that's causing the problem. And, you've proven it isn't the fuel, so that makes it easier. You've now gone a long way to insulating the carb from heat via conduction, so the next step would be a thermal shield like your friend suggested. I think someone on here or FTE had similar issues and one of those made a big difference. And they don't add much height.

 

[ArdWrknTrk]

On the recommendation of some people on the Bronco forum I got this insulating gasket. The first issue I had was that my mounting studs weren't long enough for the added thickness (~3/8"). I had some 5/16-18 ready-rod so I made new studs (maybe I'll get real studs for it some time).

Next issue I had was that I believed the website that called it a gasket. It didn't feel like a gasket to me, and I doubted it's ability to seal. But I put it between the carb and manifold anyway and started it up.

Spraying carb cleaner around the base of the carb showed a whole lotta vacuum leaks. Fortunately I had a couple of stock gaskets. So I put one on either side of the new "gasket" (more of a spacer really) and tried again. No leaks this time!

It's definitely better now, but not perfect. I stopped for gas (engine definitely up to temp) and when I restarted it took quite a bit of cranking, but did start without my needing to hold the throttle open. (This was running on the aux tank that was empty over the winter and filled a few weeks ago. So it was fresh-ish regular 87 octane E10)

At the gas station I filled it with non-oxy premium and switched to the main tank (which had been empty), so the next test was with fresh non-oxy. Again with a hot engine I leet it heat soak while I ran in to NAPA to get pads and rotors for my son's car. And again it started without holding the throttle open, but with a lot of cranking.

So like I said, better but not perfect. I'll live with it like this for the foreseeable future. And I now know that there's no point in chasing down the much more expensive non-oxy fuel.

Bob, you're not the only one having hot restart trouble.

It would be interesting to have a definitive answer.

[Nothing Special]

Bob, you're not the only one having hot restart trouble.

It would be interesting to have a definitive answer.

It would be interesting, but I doubt I'm going to find it, because I don't think I'm going to do much more looking. It's currently better than my '85 F-250 ever was (351W, Motorcraft 2100 or 2150 2 bbl carb). Hot restarts on that involved pumping the gas to give a good shot of fuel to get it good and flooded, then hold your foot on the floor while cranking to clear the flood. I described that as "the dance."

[Nothing Special]

It would be interesting, but I doubt I'm going to find it, because I don't think I'm going to do much more looking. It's currently better than my '85 F-250 ever was (351W, Motorcraft 2100 or 2150 2 bbl carb). Hot restarts on that involved pumping the gas to give a good shot of fuel to get it good and flooded, then hold your foot on the floor while cranking to clear the flood. I described that as "the dance."

I'm touching on this in the trip report from the trip to Moab that I just made with the Bronco, but I thought I ought to keep this complete too.

The Bronco worked great on the trip! No significant issues at all!

I started the trip with the .052" jets in the carb. It was difficult to restart hot so I went down to the .050" jets. It was maybe a little better on hot restarts, and certainly wasn't giving me any indication that it was too lean. Now that I'm home (~700' elevation rather than Moab's 4,000') I haven't got around to switching the jets, but it's still running good. So maybe my problems all along were that checkball weight?

Anyway, it still needs a bit of throttle to start when hot, but it's very tolerable.

Last summer I got new tires for 'wheeling (33/12.50-15 Pro-Comp Xtreme MT). I used them on my trip to SMORR last year and liked them on the trails, but I was getting too much vibration at some highway speeds to feel good about flat-towing it (where it would shake itself apart while I had no idea it was happening). I need to get that issue resolved, but for this trip I used my worn-out 33/10.50-15 BFG AT KOs. I was slightly concerned about them living through the highway miles, but thought they'd make it, and they did. Off-road they were fine (Utah "slickrock" gives phenomenal grip to everything except steel horseshoes and wagon wheel rims, which was what was being used when it was named "slickrock"). But I will need new tires soon. I'm going to try to hold out until next spring. I'm thinking I'll get some 235/75-15 in an all-season tread. Smaller and less aggressive for road use since I have the bigger more aggressive tires for off-road use rather than the ATs as a compromise for both.

Oil leaks have been a big issue for me forever, so it's notable that I made it through this trip without needing to add any oil! However I did need to add brake fluid twice (I have the relatively new hydroboost on it). I have enough oil spread over the entire underside that small leaks aren't obvious, but I need to figure out where it's leaking.

But that's about all I have to report. It went everywhere I pointed it, including quite a few lines that I wouldn't have tried before (I'm continuing to gain confidence). I did use the front locker quite a bit (I was on lines where I REALLY didn't want to fail and have to slide back down!) compared to my last trip to Moab when I only used it 3 or 4 times. But I did crawl* every obstacle I attempted on the first try, except for one. There was one ledge that wasn't very high or very steep so I was surprised I couldn't crawl it, but it was dusty so my tires didn't bite as well. That one took a small "bump", but I did make it up on my second attempt.

* You get style point for crawling up obstacles instead of hitting them hard. It's also a lot easier on the equipment. It's usually not possible in mud, snow or sand, and sometimes isn't in rocks. But it's always my goal.

[Gary Lewis]

I'm touching on this in the trip report from the trip to Moab that I just made with the Bronco, but I thought I ought to keep this complete too.

The Bronco worked great on the trip! No significant issues at all!

I started the trip with the .052" jets in the carb. It was difficult to restart hot so I went down to the .050" jets. It was maybe a little better on hot restarts, and certainly wasn't giving me any indication that it was too lean. Now that I'm home (~700' elevation rather than Moab's 4,000') I haven't got around to switching the jets, but it's still running good. So maybe my problems all along were that checkball weight?

Anyway, it still needs a bit of throttle to start when hot, but it's very tolerable.

Last summer I got new tires for 'wheeling (33/12.50-15 Pro-Comp Xtreme MT). I used them on my trip to SMORR last year and liked them on the trails, but I was getting too much vibration at some highway speeds to feel good about flat-towing it (where it would shake itself apart while I had no idea it was happening). I need to get that issue resolved, but for this trip I used my worn-out 33/10.50-15 BFG AT KOs. I was slightly concerned about them living through the highway miles, but thought they'd make it, and they did. Off-road they were fine (Utah "slickrock" gives phenomenal grip to everything except steel horseshoes and wagon wheel rims, which was what was being used when it was named "slickrock"). But I will need new tires soon. I'm going to try to hold out until next spring. I'm thinking I'll get some 235/75-15 in an all-season tread. Smaller and less aggressive for road use since I have the bigger more aggressive tires for off-road use rather than the ATs as a compromise for both.

Oil leaks have been a big issue for me forever, so it's notable that I made it through this trip without needing to add any oil! However I did need to add brake fluid twice (I have the relatively new hydroboost on it). I have enough oil spread over the entire underside that small leaks aren't obvious, but I need to figure out where it's leaking.

But that's about all I have to report. It went everywhere I pointed it, including quite a few lines that I wouldn't have tried before (I'm continuing to gain confidence). I did use the front locker quite a bit (I was on lines where I REALLY didn't want to fail and have to slide back down!) compared to my last trip to Moab when I only used it 3 or 4 times. But I did crawl* every obstacle I attempted on the first try, except for one. There was one ledge that wasn't very high or very steep so I was surprised I couldn't crawl it, but it was dusty so my tires didn't bite as well. That one took a small "bump", but I did make it up on my second attempt.

* You get style point for crawling up obstacles instead of hitting them hard. It's also a lot easier on the equipment. It's usually not possible in mud, snow or sand, and sometimes isn't in rocks. But it's always my goal.

Good report, Bob. And I suspect the weight was the problem all along. Jetting shouldn't make much difference in restart, but the weight will.

[Nothing Special]

Good report, Bob. And I suspect the weight was the problem all along. Jetting shouldn't make much difference in restart, but the weight will.

Gary and Dane (grumpin) complimented my Bronco's abilities off-road in my 2021 Moab trip report. I wanted to comment on that, but thought it might fit better in my project thread.

As far as my Bronco's articulation, it's pretty good in the rear axle, but if you look at the front axle in the picture Gary was looking at, there's really no articulation there (it's more obvious in some earlier pictures I've posted where the picture is from the front when it's all crossed up). In an early Bronco front suspension, like the F-100/F-150 4WD suspensions of the same era, the front axle housing acts as a REALLY stiff antisway bar. I'd been thinking about going to a long arm or 4-link front suspension to address that. But I'm starting to think it's not worth it. Because it really is working well overall, even with no front axle articulation.

It really doesn't have that many modifications that directly impact its off-road capabilities. But the modifications it has are pretty important ones:

It has about a 3" suspension lift and 1" body lift, both installed by a previous owner. I'm sure that helps with the rear articulation. It also makes room for...

... its 33" tires. Those are pretty small by 'wheeling standards (where 37s seem to be the price of admission these days and 40s increasingly common). But they are a lot bigger than the ~28"(?) tires that would've been stock. So nothing extraordinary, but still an important modification.

I'm running the stock axle ratio, but it came with 4.10s, so it wasn't bad from the factory there.

The most important mods though are the diffs and transfer case. I've got true lockers in both axles: a Detroit automatic locker in the rear and an OX selectable locker in the front. I'm coming to think that an automatic locker in the front and selectable in the rear might be a more effective setup for rock crawling, but any lockers are a huge help in the rocks, and I do really like this setup.

And the Atlas 4.3:1 transfer case was a HUGE improvement. It let’s me crawl over big rocks rather than bouncing off them. That gives WAY more control and is a lot easier on the equipment, as well as being a lot more comfortable for the driver and passengers.

And I suppose I should mention the NV3550 5 speed trans. 1st gear is slightly lower than the stock 3 speed which helps a little with crawling. And the overdrive makes highways more pleasant, as well as letting me stay in low range on the smooth sand sections of the trails I was just on. I really like it as a mod, but it really doesn’t have much impact on the Bronco’s abilities.

That’s really about it for mods that help with its off-road capability. However there are others that reduce the chances of breakage, help with recovery or make it safer to ‘wheel:

Axles are sort of stock, but the 9" rear (even though it's a small bearing) and Dana 44 front are pretty stout starting places. And I am running chrome-moly axle shafts in both ends.

The rock slider on the passenger side (and I’m finally starting to work on the driver’s side) protects a vulnerable area.

Bumpers that will support the Bronco on a Hi-Lift jack as well as providing recovery points and a hitch receiver at both ends make hitting rocks less concerning and helps with recovery.

The receiver-mount winch hasn’t been used much (not at all in this past trip) but it provides some peace of mind, and is a huge help when it’s needed.

And the full roll cage, along with high-backed seats and seat belts with shoulder harnesses provide a needed measure of safety.

I don’t have a very long list of other mods that I feel it needs. I do want to give it a tummy tuck (the drop radius arm mounts have hung up a lot on earlier trips, and the transfer case isn’t much higher). And I want to add some skid plating to the trans / transfer case area. But that’s really it. Then I hope to primarily move on to other vehicular projects (although I’m sure there will be on-going repairs on the Bronco).

 

[oldmansimek]

Gary and Dane (grumpin) complimented my Bronco's abilities off-road in my 2021 Moab trip report. I wanted to comment on that, but thought it might fit better in my project thread.

As far as my Bronco's articulation, it's pretty good in the rear axle, but if you look at the front axle in the picture Gary was looking at, there's really no articulation there (it's more obvious in some earlier pictures I've posted where the picture is from the front when it's all crossed up). In an early Bronco front suspension, like the F-100/F-150 4WD suspensions of the same era, the front axle housing acts as a REALLY stiff antisway bar. I'd been thinking about going to a long arm or 4-link front suspension to address that. But I'm starting to think it's not worth it. Because it really is working well overall, even with no front axle articulation.

It really doesn't have that many modifications that directly impact its off-road capabilities. But the modifications it has are pretty important ones:

It has about a 3" suspension lift and 1" body lift, both installed by a previous owner. I'm sure that helps with the rear articulation. It also makes room for...

... its 33" tires. Those are pretty small by 'wheeling standards (where 37s seem to be the price of admission these days and 40s increasingly common). But they are a lot bigger than the ~28"(?) tires that would've been stock. So nothing extraordinary, but still an important modification.

I'm running the stock axle ratio, but it came with 4.10s, so it wasn't bad from the factory there.

The most important mods though are the diffs and transfer case. I've got true lockers in both axles: a Detroit automatic locker in the rear and an OX selectable locker in the front. I'm coming to think that an automatic locker in the front and selectable in the rear might be a more effective setup for rock crawling, but any lockers are a huge help in the rocks, and I do really like this setup.

And the Atlas 4.3:1 transfer case was a HUGE improvement. It let’s me crawl over big rocks rather than bouncing off them. That gives WAY more control and is a lot easier on the equipment, as well as being a lot more comfortable for the driver and passengers.

And I suppose I should mention the NV3550 5 speed trans. 1st gear is slightly lower than the stock 3 speed which helps a little with crawling. And the overdrive makes highways more pleasant, as well as letting me stay in low range on the smooth sand sections of the trails I was just on. I really like it as a mod, but it really doesn’t have much impact on the Bronco’s abilities.

That’s really about it for mods that help with its off-road capability. However there are others that reduce the chances of breakage, help with recovery or make it safer to ‘wheel:

Axles are sort of stock, but the 9" rear (even though it's a small bearing) and Dana 44 front are pretty stout starting places. And I am running chrome-moly axle shafts in both ends.

The rock slider on the passenger side (and I’m finally starting to work on the driver’s side) protects a vulnerable area.

Bumpers that will support the Bronco on a Hi-Lift jack as well as providing recovery points and a hitch receiver at both ends make hitting rocks less concerning and helps with recovery.

The receiver-mount winch hasn’t been used much (not at all in this past trip) but it provides some peace of mind, and is a huge help when it’s needed.

And the full roll cage, along with high-backed seats and seat belts with shoulder harnesses provide a needed measure of safety.

I don’t have a very long list of other mods that I feel it needs. I do want to give it a tummy tuck (the drop radius arm mounts have hung up a lot on earlier trips, and the transfer case isn’t much higher). And I want to add some skid plating to the trans / transfer case area. But that’s really it. Then I hope to primarily move on to other vehicular projects (although I’m sure there will be on-going repairs on the Bronco).

Nice looking bronco I have a few myself ranging from garbage to in pieces. I saw you mentioned your front end travel, it looks like from your pictures your running stock radius arms with drop brackets? I have never really figured out why sometimes the stock style flex really well and some don't move, but I have found that the bloody knuckle or james duff long arms completely solve this problem.

This is not my truck but I have the same long arms on my 84 that I did a sas on and I have at least 14" travel.

[Nothing Special]

Nice looking bronco I have a few myself ranging from garbage to in pieces. I saw you mentioned your front end travel, it looks like from your pictures your running stock radius arms with drop brackets? I have never really figured out why sometimes the stock style flex really well and some don't move, but I have found that the bloody knuckle or james duff long arms completely solve this problem.

This is not my truck but I have the same long arms on my 84 that I did a sas on and I have at least 14" travel.

Thanks!

Yes, I'm running stock front suspension except for taller springs and drop brackets for the radius arms and track bar.

I was thinking about going with a long arm kit, but there really aren't many (if any) still available for early Broncos. I don't know if that's a supply and demand thing or if there's some other reason they fell out of favor.

So my current plan is to stick with the stock radius arms and go back to stock mounts to get them up higher. That will screw up my steering geometry (which is why I added the drop brackets in the first place), so I plan to address that with a cut-and-turn on the axle housing. While I'm doing that I plan to rotate the pinion up to improve my driveshaft angles so I can (hopefully) clock the transfer case up higher to improve the clearance under the t.case.

I know that won't articulate like you show in that picture. But it does work well now on the trails I want to do. And it handles pretty well on the highway too. So I'm thinking this will put me in a pretty good place for what I want.

[oldmansimek]

Thanks!

Yes, I'm running stock front suspension except for taller springs and drop brackets for the radius arms and track bar.

I was thinking about going with a long arm kit, but there really aren't many (if any) still available for early Broncos. I don't know if that's a supply and demand thing or if there's some other reason they fell out of favor.

So my current plan is to stick with the stock radius arms and go back to stock mounts to get them up higher. That will screw up my steering geometry (which is why I added the drop brackets in the first place), so I plan to address that with a cut-and-turn on the axle housing. While I'm doing that I plan to rotate the pinion up to improve my driveshaft angles so I can (hopefully) clock the transfer case up higher to improve the clearance under the t.case.

I know that won't articulate like you show in that picture. But it does work well now on the trails I want to do. And it handles pretty well on the highway too. So I'm thinking this will put me in a pretty good place for what I want.

With 33's you should not need the drop brackets. my buddies 71 has I believe the 6" (not positive) springs from james duff and we did not do drop brackets I used the offset c bushings for the radius arms and his truck flexes great he is running 35's but they do rub a bit. I just got a set of the long travel radius arms from bloody knuckle garage, he designed and made the ones that james duff sells.

[Nothing Special]

With 33's you should not need the drop brackets. my buddies 71 has I believe the 6" (not positive) springs from james duff and we did not do drop brackets I used the offset c bushings for the radius arms and his truck flexes great he is running 35's but they do rub a bit. I just got a set of the long travel radius arms from bloody knuckle garage, he designed and made the ones that james duff sells.

When I bought this Bronco it already had a suspension lift (I'm not sure but about 3"), a power steering conversion using an F-series steering box (which drops the pitman arm quite a bit) and no drop brackets for the track bar or radius arms.

It actually drove and handled pretty well, but it did have pretty terrible bump steer and I couldn't flat tow it very well. When I'd turn flat towing the wheels would go to full opposite lock in a turn (when I needed to flat tow it I'd tie the steering wheel so it would stay straight).

Adding a track bar drop bracket got the track bar and drag link parallel and took care of my bump steer.

I had the alignment checked and it had several degrees of negative camber. That's what was making it turn the opposite way when flat towing (it's shocking that it handled as well as it did). I got C-bushings with the most offset I could get and that only brought my camber to about 0 and it still didn't flat tow very well. So I added the radius arm drop brackets and was able to dial in the camber to spec (something like 4 degrees? I don't remember exactly).

I had considered a cut-and-turn at that time, but that was a little more than I wanted to try to tackle at that point in my life. I also considered a long-arm kit, but they were out of my price range. So the drop brackets got the nod as being good enough and affordable.

In hind sight of course I wish I'd dome something different so I didn't have to redo it now. But realistically I did the best I could at the time. But now I can do better.