1968_Post

Question about replacing the u-joints in my 1968 442...

GM Parts Catalog show the joints as the same for front and rear. This is what I remember from back in the day. When looking at Rock Auto and other suppliers, the listing calls for 2 different numbers and a slight size difference in the size of the joint from front to rear. I tried using the GM number (7806140) as a cross reference, but to no avail.

Anyone have any input? This is a TH400 car, not that it should matter.

Thanx,

Jeff

oddball

Huh. Looks like you'll have to crawl under there to take a look.

Most Olds driveshafts used 3R u-joints on both ends. RockAuto is listing conversion U-joints - 3R on one leg, and I assume 1330 on the other leg - for the rear and (I assume) a 1330 for the transmission yoke - only for the 455. For the 400 it's all 3R's.

Here's some specs that can help when you measure what you've got:
http://www.driveshaftspecialist.com/...D%20Guide.html

No one can really tell you what you have. If the driveshaft has ever been replaced, worked on, modified, whatever, it may have a different mix of u-joints.

oldcutlass

Replace the Ujoints with the same ones that came out. I believe Canadian cars came with a Chevy 12 bolt which is probably why they list the different part numbers.

Yellowstatue

Canadian 442's come with Olds axles.

joe_padavano

No, they did not. The Oshawa-built 442s came with a Chevy 12 bolt, not a Type O. This is documented in the CSM and the factory parts book. My first 442 was an Oshawa-built 1968 and it came with the Chevy axle.

Yellowstatue

Yes they did. Both my '68 442's came with Olds axles, and I bought a 3:91 Olds axle out of another Oshawa built '69 442.

Ozzie

My experience with U-joints says to remove the ones you have, take them to the place of purchase, compare the new to the old and try to get some with grease fittings. So far I've never had to replace a well greased u-joint.

ronskal

Going through this now on my 70 442, I'll try to help.
The 68 CSM talks about removing retaining rings then popping out the u-joints. That can be confirmed by visual inspection, noting that the retaining rings should be on the inside of the yoke, C shaped clips. Might have to clean it good to see. The ones RA sells for your car all are this style, internal C-clip (if their photos are accurate).
My 70 has 2 different possible styles and I got one of the wrong ones, cannot 100% trust the websites- talking to myself here.............

1968_Post

Thanks ronskal, finally a reply that addressed my actual question. This car had the wrong engine (350) and trans (th350) so the shaft that was in it was no help. The shaft I bought to match the TH400 came with no rear joint so I couldn't figure which joint I needed. What I couldn't tell from the listings was whether the joint had 4 cups the same size or 2 large and 2 small. I ended up buying joints locally, buying both types and deciphering which were correct. Joints went in today, shaft is back in the car and everything is good. Thanks for your reply.

oldcutlass

Glad you got it figured out.

monzaz

Jeff, You always need to remember how old these vehicles are which get parts swapped and that even from the factory things deviate on NEW CARS.
There is only a few u-joints that it will be.
You need to measure your cup outer diameter sizes (normally 1.125 or 1.062)
Normally you should have 2 the same 1.125 (also known as a mechanics 3R u-joint) This u-joint is GMs most common u-joint and will be in all the 1/2 ton pick-up trucks s-10 1979-1989 cars f-body g-body b-body etc. It is known back in the day as the BOP joint
1.062 was always known as the Chevy u-joint and Chevy had 2 1310 or 1330 which was the big block joint...this joint had a larger cross shaft width than the 1310 smaller cross shaft.

NOW- if you have a 1.062 x 1.125 they have a combination u-joint so do not fret it is a Moog 372 and will have one side with the mechanics 1.125 cups and the other cross is Chevy 1.062 cups narrow 1310 joint-

I am sure they have a mechanics3r with 1330 cross also.

Hope this helps others and did not confuse you more.

Glad you got the parts all figured out also...

Jim - J D Race

Jim

1968_Post

Thanks Jim...

I think my confusion came from not knowing what the shaft I'm using was out of. All I knew is that the length was correct as were the splines on the front yoke. Once I got beyond that, everything fell in place. The car has some sort of sordid past that has been interesting to overcome. Junkyard engines/transmissions and indiscriminate installations can get interesting.
I appreciate your input and explanation!

monzaz

Yah I just try to give info incase someone googles or searches the web site for the same issues. Jim

briane

If you have the time, watch the 7-part series from Weber University's Automotive Program on U-joints. I learned a lot on identifying a quality part, select fit of the retaining clips, and more. Lots of quality information in their videos.
https://www.youtube.com/watch?v=v0RZVQQVMZs