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Need slip yoke help

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Jacob84

Need slip yoke help

Hey guys. I've been battling a pretty bad vibration lately and have determined that the most of it is the slip yoke that goes into the transfer case. It has a good amount of play in it. I have another one from a 95 f150 parts truck so I wasn't too concerned but when I was checking it out it, had a lot of rust on it and it also has play in it. I need to find a new one.

My problem is that I am having trouble finding a new one. I tried finding a part number on the existing slip yoke but could not find one. I also am unable to find a listing at any parts store.

The truck is a regular cab long bed, 133" wheel base, 351W, C6, NP208 transfer case, Ford 9 inch, one piece driveshaft, and I believe 1330 style u-joints.

I found listings for 31 spline slip yokes for a C6, which I have, but of course the slip yoke goes into the transfer case because it's 4x4.

Does anybody have a good idea as to where I can find a new one? I've searched Summit, Speedway Motors, Oreilly's, RockAuto, Broncograveyard, haven't found one for my application.

Jacob,
84 F150 base model, New 95 roller 351w with 5.0 ho roller cam, Summit Racing Max EFI 500, and other toys, MSD DIS, C6 trans, 9 inch rear 3.50, reg cab, long bed, 4x4. 33s, 2.5" Rough Country lift.

Gary Lewis

Re: Need slip yoke help

Administrator

I think you are going to have to take it to a driveline shop. I say that because I've not seen the yoke that goes into the transfer case or the transmission wear out. That's because they are kept wet by the lube in the t-case or transmission. However, if the yoke is worn, like maybe someone ran things dry, then the output shaft of the t-case is probably also worn just as much.

But, if you want to find the yoke go to the page at Documentation/Driveline/Driveshafts and click on the Applications tab. Then scroll down to Page 19 where you'll find the F150 4wd's w/a C6. And there I see, as shown below, four different possibilities that match the info you've given.

So you'll have to measure your driveshaft to see which yoke you have. IOW, is yours 31 17/32; 32 17/32; etc?

Then, with the yoke # scroll back to the top and click on the Slip & Flange Yokes tab and you can find the part number for it.

(See why I can't look everything up for everyone? Too much info is needed that you won't think to give me. Hence the reason I put the info online so you can look it up.

)

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

ArdWrknTrk

Re: Need slip yoke help

Administrator

In reply to this post by Jacob84

Jacob,

I've been offline for a while, and while I can't guaranty I have all this right, I would like to say that the C4 slip yoke is the one you want, for the following reasons:

The output bushing on a slip yoke 208 is 38mm (1 1/2") and the 208 comes with 28 splines.
F 150's have a 1310 series universal, while the flange double cardan on a Bronco is 1330.

Your driveshaft universal may use a conversion (or bastard) U-joint.
Ford was notorious for this, and it almost left me stranded in Greenfield a few months back.

So, measure up the diameter and count the splines starting with the missing tooth.

Also, if you have a sloppy yoke be sure to replace that output bush.
It's under $10.

My only other advice is to actually call JBG.
When I dropped my driveshaft and sent it to get a new end welded on the driveline shop got me the wrong one, and the staff at Jeff's got it figured out and had one drop shipped from Dana/Spicer that day.

Definitely came through in the clutch!

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Need slip yoke help

Administrator

Way over my head, Jim. Good advice.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Need slip yoke help

Administrator

Remember, the internet is full of "experts" and my advice is worth exactly as much as Jacob paid for it.

I looked up exploded parts for a 208 in an '84 F-150.
Came up with a 28 spline output and that the bushing was 38mm ID.

When I started looking for F-150 output yokes I noticed (on LMC) that this seems the same as a C4 slip yoke.
I may well be wrong... but I did check a couple of parts breakdowns for the TC, and I do think 28 spline and 38mm is correct for his application.

JBG was very helpful to me when I got stuck with the wrong one and the driveshaft shop was just scratching their head.
So give them a call. No one is going to complain about factory direct Spicer parts.

If it is sloppy, the bush HAS to be worn.
Maybe just getting a bush and trying its fit on the existing yoke will be enough? IDK
Bronze is meant to wear, and you're not even out the <$10 because it needs replaced.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Jacob84

Re: Need slip yoke help

Gary- sorry about the late reply but thank you. I looked through the documentation before I posted and it makes a lot more sense now!

Jim- Although the advice came with no price tag it’s getting me somewhere! I appreciate it. I’ll be doing some more investigating and I’ll take your advice! Hopefully know more soon!

Jacob84

Re: Need slip yoke help

Hey guys. I’m having a really hard time finding the slip yoke bushing for the tail housing on the NP208. I’ve searched all sorts of parts places, the documentation, illustrations, forums, etc. Is it an actual bushing or is it a bearing like a needle bearing? I’d pull the driveshaft and look but I haven’t had a chance. I think all I am seeing is stuff that has a fixed yoke, no slip yoke.

Am I missing something? I figured I’d take Jim’s advice and replace the bushing first and see if that fixes my vibration but I can’t find it for the life of me.

Gary Lewis

Re: Need slip yoke help

Administrator

Wouldn't that be 7A034 in this illustration from Documentation/Driveline/Transfer Case and then the NP208 and Illustrations tab? If so, go to Part Lists tab and it will show you the part number.

Gary, AKA "Gary fellow": Profile

Rembrant

Re: Need slip yoke help

If I'm understanding Gary's part number listings correctly, this should be the bushing?

https://www.ebay.com/itm/NOS-1984-1991-FORD-F150-F250-BRONCO-BORG-WARNER-TRANSFER-CASE-REAR-BUSHING-NEW/143005385820?epid=1911202815&hash=item214bc9045c:g:2oYAAOSwTVlb44vr

Should be available aftermarket though.

My slip yoke is a little looser than I'd like it to be. I'm not sure what is normal though...

1994 F150 4x2 Flareside. 5.0 w/MAF, 4R70W, stock.
1984 F150 4X2 Flareside. Mild 302 w/ 5spd. Sold.
1980 F150 4X4 Flareside. 300i6 w/ 5spd. Sold in 2021.
1980 F100 4X2 Flareside. 351w/2bbl w/NP435. Sold in 1995

Jacob84

Re: Need slip yoke help

Gary- Thank you sir, don’t know how I missed that. As my dad says jokingly “buy you books, buy you books, send you to school, now look at you”. Hopefully next time I’ll be able to manage it by myself😂

Rembrant- that seems to be correct, what’s curious to me is that I can’t find that bushing aftermarket. Only NOS or used. Maybe that bushing was used in a different application like a 2wd transmission tail housing. Currently on the search. I’ve always had a small vibration but once I lifted the truck it went downhill very quickly.

Gary Lewis

Re: Need slip yoke help

Administrator

My father was wont to say "Buy you books and buy you books, and you eat the covers off."

Anyway, glad it helped. Good luck!

Gary, AKA "Gary fellow": Profile

Rembrant

Re: Need slip yoke help

In reply to this post by Jacob84

Jacob84 wrote

Rembrant- that seems to be correct, what’s curious to me is that I can’t find that bushing aftermarket. Only NOS or used. Maybe that bushing was used in a different application like a 2wd transmission tail housing. Currently on the search. I’ve always had a small vibration but once I lifted the truck it went downhill very quickly.

I took my driveshaft to a driveline shop earlier this year to have the balance checked. Not only did they find it out of balance they said it was also bent. No idea how that happened...it looked fine. Anyway they straightened it and rebalanced and it make a big difference in reducing my driveline vibration.

Bruce moose4x4

Re: Need slip yoke help

In reply to this post by Gary Lewis

My transfer case parts breakdown show a WT297-62 bushing for a 208 transfer case. 2.010 OD, did not give ID.
https://www.summitracing.com/parts/mgr-wt297-62

Bruce aka Moose--1978 F250 LWB Flareside, Dana 60's w/ 4:10's, 460, c6