View Full Version : Seals

03-29-2005, 09:15 PM
Hey guys,

I have to machine down a drive shaft yoke, but i do not know how much i should leave on it so the seal will have the proper contact pressure on the newly machined yoke. Any suggestions would be appreciated.

Rob http://bbs.homeshopmachinist.net//smile.gif

03-30-2005, 04:08 AM
Is there a sleeve available from your local auto parts store or is it not appropriate in this application?

03-30-2005, 06:51 AM
The yoke is too big. I have to machine it down so it will fit in the tail end of the transmission. My buddy is installing a Tremec 5 speed in his 66 Malibu.

Finding the correct yoke has been like pulling teeth. He has two purchsases that have not panned out, and he is someone who realy reaserches something before he buys it.

Rob http://bbs.homeshopmachinist.net//smile.gif

03-30-2005, 08:34 AM
Rob, that's funny! I just had a guy at work ask me about putting a newer 5 speed into his 67 Olds. I claimed ignorance of course because I've never done one.
If yolks are that hard to find then what the heck is the tranny out of? I've built a lot of wierd things over the years and have found that there is often a conversion U-joint made. Is this a possibility here?
Right now I'm doing a Toyota 4x4/4.3 Chevy swap. Conversion joints are available for this. I'm thinking that older Chev and new 5 speed trannies is a common swap.
Ha....now I can tell the guy at work that "I'm all over it" http://bbs.homeshopmachinist.net//biggrin.gif

03-30-2005, 08:43 AM
Well measure the seal's(new one)ID.It should be close to something either SAE or metric,then turn to that size.

03-30-2005, 11:20 AM
Up here in canada we make some nice hats from the seals we club. Slippers also.

03-30-2005, 11:49 AM
If you can find a good auto parts store (NAPA or and old Mom & Pop place), they should have a specification book for seals. It will have the intended shaft size for any part number. An industrial bearing supplier should have the info as well.


03-31-2005, 05:02 PM
Hey everyone,

I can get the seal. No problem. I have the part number and all the info. I would like to know what is an acceptable friction fit.

Example. If the seal measure 2.000" should the yoke have an outer measurement of 2.001" or 2.002"

My buddy has a 66 chevelle with a 454 500hp motor. His is installing a new tremec 5 speed. Of course these don't come with the yokes. His automatic yoke is too big to fit in. The one i want to machine down.

He did buy one off of Ebay but the iner splines don't seem to be cut the same. Their inner dimesion is too small for the output shaft in the transmission

Rob http://bbs.homeshopmachinist.net//smile.gif

03-31-2005, 05:59 PM
If wou know the seal # then simply look up what size shaft it is designed for.

Most transmissions also have a bushing in the tailhousing so that is what I would worry about.


04-01-2005, 12:32 AM
Yep, finding the right yoke is a common problem. They're diffent lengths, OD's and splines. Just because it's a GM doesn't mean a GM yoke will fit. There's different models of Tremec's; Which model is it?

Seals are sold/designed to fit a given shaft size depending on the seal type and application. If you have a 2" shaft, you buy a 2" seal. The ID of seal may actually be 1.980 when measured without compression. The clearance varies by type of seal (K, L, C, etc.) and the pressure applied to the contact area.

I'd start out a little large like .030-.040" oversize. Oil the shaft/seal and try it. It should be snug without causing the seal to roll on in/out movement. Just make sure the seal contact area is polished smooth. If it's too tight, take off .005, polish and try again.

04-01-2005, 10:00 AM

I have the part number for the seal, but GBS is having trouble tracking it down. Not like them. They asked what it is out of. What a can of worms that questions opened. So we tracked down what the housing was from, etc etc. Nope, no luck.

I have been trading the information over the internet and phone. I figure i might have to go over to my buddy's garage and get the info myself. Sometimes it is hard to explain what to look for over the phone.


Thanks for the hint. that is basically what i wanted to know. I never thought it would be that much of an interference fit.

Rob http://bbs.homeshopmachinist.net//smile.gif

04-01-2005, 11:38 AM
If you give me the part # on the seal (GM, National, CR... whatever)I may be able to find the info you need.


04-01-2005, 12:08 PM
Tremec's use the same yokes as C-6 automatics and the newer T-45 and 3650 trannys that are in mustangs, it should be easy to find a yoke that will match your u-joint configuration. if not, then spicer makes special u-joints with different sizes on each axis. machining the hardened and ground surface of the yoke would be a VERY LAST option.

[This message has been edited by cliff69 (edited 04-01-2005).]

04-02-2005, 12:50 AM
I'll ditto cliff69, I have a Tremec 3550 in my vintage Mustang and it uses a C6 yoke...The 3550's are pretty popular so you shouldn't have too much problem getting a junk yard solution. Darkhorse performance is pretty knowledgeable on these things if you want to go retail, Mark Williams is my first stop if I have cash, and I bought my 7075 aluminum yoke from Inland Empire Driveline.

04-02-2005, 01:41 AM
The T-35xx can have different tailshafts. It may have a Ford 28 or 31 spline. If it's the 28, you can use the C-4 or C-6 automatic yoke.