Author Topic: 9 inch rearend and yoke questions (Read 589 times)

JBauer4363 · « **on:** February, 24, 2010, 05:37:29 PM »

I really messed up. The 9 inch open rearend thats in my Mustang has been noisy since I put it in and I decided to replace it. I bought a rebuilt one off ebay to replace it and today I got it. I never gave it a thought about the yoke and of course its different than my old rear. The new one has a short yoke and the old one is long. What will I have to do to get the driveshaft to work. Looks like the difference is about an inch.

What sucks is I bought the new rear because everyone locally that I asked about rebuilding the old one wasnt interested or wanted as much as I payed for the new rear.

How bad is this?

Thanks in advance.

monkeystash · « **Reply #1 on:** February, 24, 2010, 06:27:03 PM »

I'm not an expert by any means, but I'm pretty sure you can just swap the yokes. You will need a new crush collar and have to reset the pinion bearing preload. Here is some info:

http://www.differentials.com/install.html

66gt350 · « **Reply #2 on:** February, 24, 2010, 07:57:36 PM »

That's no problem at all. When I ordered my new rear, I thought that I had the short yoke, so that's what I got. When I got it home I needed the long yoke. The suspension shop ordered the correct one and swapped it. Just cost me a little extra money, since I had to order 2 yokes.

Anyone need a yoke, installed but never put on the car...

JBauer4363 · « **Reply #3 on:** February, 24, 2010, 08:10:12 PM »

Ya that would be easy but the shop i bought it from is long distance and the part is heavy. shipping $85 each way plus the instal :cry

66gt350 · « **Reply #4 on:** February, 24, 2010, 09:11:44 PM »

Since you have the correct yoke on the old 9", you could use it on the new pumpkin. Does the new pumpkin have a pinion crush collar or does it have a newer style solid collar? The new pumpkin I bought (with the wrong yoke) has a solid pinion collar. When the shop got the new one in, all they had to do is impact off the wrong yoke and install the new one. So far, I've got about 1000 miles on the rear end with no problems.

buening · « **Reply #5 on:** February, 25, 2010, 05:21:25 AM »

.....and then there is the old school way of swapping the yokes and torquing the nut down to 100ft-lbs without a new crush collar. Not that I condone this but may old school guys do this and don't have a problem. No guarantee that the gears will mesh perfectly as before though.

sigtauenus · « **Reply #6 on:** February, 25, 2010, 09:55:51 AM »

I think the old school way is assuming you are putting the same parts back together and just changing out the seal.

It might work if the yoke depth below the flange is exactly the same on both yokes. Might be able to mic it to check and if it comes out the same give it a shot.

JBauer4363 · « **Reply #7 on:** February, 25, 2010, 06:11:20 PM »

Thanks for the help! First of all Ive got to say that I really dont know much if anything about these rearends (thats why I should always ask questions before I act on impulse and buy stuff without thinking about what Im doing). Im hoping there is a fix that I could be able to do. I took some pics so maybe you guys could tell me what Ive got.

Quote from: 66gt350 on February, 24, 2010, 09:11:44 PM

Since you have the correct yoke on the old 9", you could use it on the new pumpkin. Does the new pumpkin have a pinion crush collar or does it have a newer style solid collar?

Dont know can you tell from these pics?
old yoke:

new yoke:

Any coments are welcomed.

Thanks again.

monkeystash · « **Reply #8 on:** February, 25, 2010, 06:29:03 PM »

No you cannot tell from the pictures. The collar is located inside on the pinion gear shaft.

Another option is changing/modifying your current driveshaft. You could also have one made or maybe find one with the correct length.

66gt350 · « **Reply #9 on:** February, 25, 2010, 06:39:39 PM »

Unfortunately, monkeystash is right...can't tell without ripping it apart. If you're unsure about doing it...is there a shop that you could take the pumpkin and long yoke locally to have 'em swap out yokes? I wouldn't think that a shop would charge you very much for doing that.

JBauer4363 · « **Reply #10 on:** February, 27, 2010, 03:02:46 AM »

Couldnt get anyone around here to work on my old rearend is why I decided to just get the new one.

This may be a DUMB question but what about the other end of the driveshaft? I mean its only an inch could I get a little longer yoke at the transmission? Do they make one?

Thanks

sigtauenus · « **Reply #11 on:** February, 27, 2010, 05:36:41 AM »

From what I've seen the slip yokes go a long way up into the transmission. If you're an inch short, just put what you have in there and see how much engagement you still have (trying to be serious and not set up a "that's what she said" line). What I mean is, if the old driveshaft gave 5 inches of engagement on the output shaft splines, and now you only have 4 inches of overlap/engagement, that may still be enough. I'm sure there is a spec out there on that, trying to find it now.

66gt350 · « **Reply #12 on:** February, 27, 2010, 06:25:47 AM »

Quote from: sigtauenus on February, 27, 2010, 05:36:41 AM

From what I've seen the slip yokes go a long way up into the transmission. If you're an inch short, just put what you have in there and see how much engagement you still have (trying to be serious and not set up a "that's what she said" line). What I mean is, if the old driveshaft gave 5 inches of engagement on the output shaft splines, and now you only have 4 inches of overlap/engagement, that may still be enough. I'm sure there is a spec out there on that, trying to find it now.

When I realized that I got the wrong yoke, I asked that question on the other mustang forum. Ideally, you want the yoke at the tranny to be out 1 inch -- 1.5 inches at the maximum. With the shorter yoke on the pumpkin, the yoke coming out of the tranny would be about 2 inches, and that is too much.

sigtauenus · « **Reply #13 on:** February, 27, 2010, 06:45:58 AM »

Yeah, now that you mention that, I do remember that from when I was ordering the new driveshaft for my T-5 conversion. I was thinking in terms of actual spline engagement vice how much of the yoke was showing outside the tailshaft, but effectively that is communicating the same thing.

ZFORCE · « **Reply #14 on:** February, 27, 2010, 07:16:50 AM »

When you remove the driveshaft from the tranny, you can see the shaft inside of the tranny. Can't you measure it to see how far inside of the tranny tailshaft it is? You can then install the new 3rd member and driveshaft engaging it, and then measure how much the the yoke slips into the tailshaft. This should give you an idea of how much engagement you will have.

Clear as mud? Don't forget, if you install your new 3rd member with it's present shaft, you lose your pinion snubber. If you swap yokes on the 3rd member, install your snubber too!

JBauer4363 · « **Reply #15 on:** February, 28, 2010, 04:50:24 PM »

Good news!! I finally heard from the shop that built the rearend. They use solid spacers instead of crush collar so (they can sell it to a dumbie like me) the yoke can be changed and not mess it up. He said all I have to do is remove the yoke thats on it and put on the one I have. He said just not to "over tighten it"... but didnt say how tight is tight. So I emailed him for that info.

Now I can put this all back together :ecit

Thanks for all the help!

monkeystash · « **Reply #16 on:** February, 28, 2010, 06:23:31 PM »

Quote from: JBauer4363 on February, 28, 2010, 04:50:24 PM

Good news!! I finally heard from the shop that built the rearend. They use solid spacers instead of crush collar so (they can sell it to a dumbie like me) the yoke can be changed and not mess it up. He said all I have to do is remove the yoke thats on it and put on the one I have. He said just not to "over tighten it"... but didnt say how tight is tight. So I emailed him for that info.

Now I can put this all back together :ecit

Thanks for all the help!

Sweet, that is good news!