1986 F-250 XLT 6.9 idi C6 switch to 300 4 speed

[nic55kel]

That is cool! The engineering is quite interesting. But how does it turn?

Would sure have been nice for many things I’ve done.

There is a steering cylinder that controls the position of the tricycle gear. The tricycle leg has a hub and bearing for the wheel of course but then there is a hub and bearing at the top that allows it to swivel.

The control valve and steering cylinder are controlled by the joystick side to side motion.

Other than the bridge over the tricycle gear the whole frame and hoist are made from salvaged 4" channel and 2x3 L sections welded together to form box sections. Lot of welding but I had a lot of time on my hands when I did it.

[Gary Lewis]

There is a steering cylinder that controls the position of the tricycle gear. The tricycle leg has a hub and bearing for the wheel of course but then there is a hub and bearing at the top that allows it to swivel.

The control valve and steering cylinder are controlled by the joystick side to side motion.

Other than the bridge over the tricycle gear the whole frame and hoist are made from salvaged 4" channel and 2x3 L sections welded together to form box sections. Lot of welding but I had a lot of time on my hands when I did it.

Thanks for the explanation. I can see how it works now.

[grumpin]

Thanks for the explanation. I can see how it works now.

Very nice! Great job on that crane!

[nic55kel]

Very nice! Great job on that crane!

Thanks Dane

[nic55kel]

Thanks Dane

All I got done on the truck today was to pull the 6.9 engine perches. Not much but something.

I did however quickly rip apart the old 6.9 to see if I could find a collapsed piston or something to account for the piston slap.

I could not really understand what I found. The pistons looked quite recent and the rings were nice and free but the bores made no sense at all - I could see no trace of any crosshatch in any bore???

The engine had obviously been apart but surely if you go to the trouble of replacing pistons and rings you would de-glaze and hone the cylinders!!!

I can't believe those are the original pistons - much too clean and unmarked.

Anyway all off to the shredder now but that had me shaking my head.

[Gary Lewis]

All I got done on the truck today was to pull the 6.9 engine perches. Not much but something.

I did however quickly rip apart the old 6.9 to see if I could find a collapsed piston or something to account for the piston slap.

I could not really understand what I found. The pistons looked quite recent and the rings were nice and free but the bores made no sense at all - I could see no trace of any crosshatch in any bore???

The engine had obviously been apart but surely if you go to the trouble of replacing pistons and rings you would de-glaze and hone the cylinders!!!

I can't believe those are the original pistons - much too clean and unmarked.

Anyway all off to the shredder now but that had me shaking my head.

I think that's exactly what they did - put new pistons and rings in an old bore. That's a waste of time and money. Frequently the rings won't seat and the bore isn't round, so ....

[nic55kel]

I think that's exactly what they did - put new pistons and rings in an old bore. That's a waste of time and money. Frequently the rings won't seat and the bore isn't round, so ....

Well had a couple of good days.

Hauled some scrap to the shredder and had a pleasant surprise. I had 3 old GM catalytic converters from behind 90's 3800s that I had scrapped a few years ago. I was thinking I would get maybe $100 each for them, $250 each yahoo.

Now these are Canadian dollars but still very nice.

I have been picking away at the donor vehicle but the fasteners on the cross member have been miserable. I got some of the fasteners out on the drivers side but then I got the cutoff wheel out and just cut off the other side. I have a better cross member so why waste time on it.

Ready to pull

Well now I know where all the fluff came from in the starter drive. There are a couple of vent holes in the bellhousing that the mice must have got in through. Just visible above the release fork.

11" clutch - ring gear is a little chewed up so will have to do something about that while it is out.

Opened up the transmission. Not as good as I had hoped but not bad for its age. I know from the PO that low gear was used quite a bit so that would explain the chipped teeth. 2 - 4 look good and the synchros all appear good, The slippers on the shift forks are all present and in nice shape.

I am thinking that I will remove the PTO cover as I believe there is a magnet on the bottom of the case and hopefully I can clean all the metal particles off it. Looking at the chipped teeth on low gear I am thinking that I could dress them with a cut off wheel to get rid of the jagged edges - using lots of rags etc. to keep debris out of the transmission. I will use low but not on a regular basis so I am sure the gear will last me the rest of my life but think it might live longer if I clean it up a bit.

Anyone have any thoughts on this?

 

[ArdWrknTrk]

Well had a couple of good days.

Hauled some scrap to the shredder and had a pleasant surprise. I had 3 old GM catalytic converters from behind 90's 3800s that I had scrapped a few years ago. I was thinking I would get maybe $100 each for them, $250 each yahoo.

Now these are Canadian dollars but still very nice.

I have been picking away at the donor vehicle but the fasteners on the cross member have been miserable. I got some of the fasteners out on the drivers side but then I got the cutoff wheel out and just cut off the other side. I have a better cross member so why waste time on it.

Ready to pull

Well now I know where all the fluff came from in the starter drive. There are a couple of vent holes in the bellhousing that the mice must have got in through. Just visible above the release fork.

11" clutch - ring gear is a little chewed up so will have to do something about that while it is out.

Opened up the transmission. Not as good as I had hoped but not bad for its age. I know from the PO that low gear was used quite a bit so that would explain the chipped teeth. 2 - 4 look good and the synchros all appear good, The slippers on the shift forks are all present and in nice shape.

I am thinking that I will remove the PTO cover as I believe there is a magnet on the bottom of the case and hopefully I can clean all the metal particles off it. Looking at the chipped teeth on low gear I am thinking that I could dress them with a cut off wheel to get rid of the jagged edges - using lots of rags etc. to keep debris out of the transmission. I will use low but not on a regular basis so I am sure the gear will last me the rest of my life but think it might live longer if I clean it up a bit.

Anyone have any thoughts on this?

I guess that's what happens when you grind it into no-synchro 1st???

SMH. Don't people understand how to double clutch and match revs?

I don't know if I would mess with it at all.

I imagine the mating input shaft gear looks worse because it's smaller?

 

[nic55kel]

I guess that's what happens when you grind it into no-synchro 1st???

SMH. Don't people understand how to double clutch and match revs?

I don't know if I would mess with it at all.

I imagine the mating input shaft gear looks worse because it's smaller?

You are right Jim I need to look at the countershaft low gear.

Hopefully I will be able to inspect it when I pull the PTO cover.

My experience with these transmissions is that low is only used from a standing start with a load or when you want to creep the vehicle. I would guess the damage was done from not letting the countershaft spin down before attempting engagement.

My solution for that is to engage 2nd to stop the countershaft and then attempt to engage low.

I can't imagine anyone downshifting from 2nd to low (more than once) while the truck is moving but who knows. I have seen pictures of these gears in much worse shape and with every tooth ground down. The picture I took is of the worst part of the gear so I think it was just something that happened only occasionally. I will let you know the condition of the countershaft gear but I don't think I will be able to get a picture.

[nic55kel]

You are right Jim I need to look at the countershaft low gear.

Hopefully I will be able to inspect it when I pull the PTO cover.

My experience with these transmissions is that low is only used from a standing start with a load or when you want to creep the vehicle. I would guess the damage was done from not letting the countershaft spin down before attempting engagement.

My solution for that is to engage 2nd to stop the countershaft and then attempt to engage low.

I can't imagine anyone downshifting from 2nd to low (more than once) while the truck is moving but who knows. I have seen pictures of these gears in much worse shape and with every tooth ground down. The picture I took is of the worst part of the gear so I think it was just something that happened only occasionally. I will let you know the condition of the countershaft gear but I don't think I will be able to get a picture.

Well I really lucked out on the clutch. It appears the clutch is brand new and the flywheel appears to be as well. I had thought that the ring gear was in much worse shape than it really is - just a couple of small chips on two teeth. Has a needle pilot bearing and I am sure the release bearing is also new (20 odd years ago).

Starting to think I will not have to do much to this drivetrain at all.

The rear main seal looks nice and dry on the engine but the oil pan and valve cover gaskets are both pretty wet so I will reseal those and while I am at it I will pull the timing cover and change the seal. I want to be sure that the cam gear is cast iron.