NJ 2002 Z28

I am just posting up to see if anyone recently purchased a PST 3.5" Aluminum Driveshaft for a Moser 12 bolt and is having any problems with the transmission Yoke???
I have one here that is to big and has ripped the seal out after as few miles during the break in for the rear..

9000th01ss

iTrader: (10)

Kind of hard to picture.
The ID of the seal has to be the same as the ID of the tail housing bushing.
If the yoke was too big it wouldn't fit into the trans.

Did you actually measure this or did someone get the DS length from an educated guess, based on others with similiar set ups?
Is it too long and shoving into the trans as the suspension compresses?

Something just doesn't make sense, I guess you're saying it's too long?

EPP

iTrader: (22)

The shop that was installing his PST driveshaft called me and said it was tight going on. I asked them it it had the same number of splines and they said it did. I told them that we have had them be a little tight before to where we had to use a rubber mallet and coax them on, but once on they free up and slide back and forth. Apparently there is more than this going on with it, we've never had one with this kind of problem, and I've sold a boatload of these driveshafts. Bob

NJ 2002 Z28

I am going to take some pictures and hopefully have them up Monday.

NJ 2002 Z28

The length of the PST drive shaft is exactly the same as the stock drive shaft but that was confirmed prior to installing..

But the yoke on the PST shaft is 2,000th of an inch larger in diameter than the stock shaft there is no clearance for bushing or for it to help lubricate..

The yoke has marks and discoloration right were the bushing is and
Judging by the marks on the yoke, the only thing we can come up with is that the yoke is getting hot and expanding due to the lack of lubrication and that expansion caused the seal to tighten up and spin with the drive shaft and pop out..
Transmission has been checked and is perfectly fine also

Stock driveshaft works perfectly fine with zero issues..

Transmission was completely rebuilt a few months ago front and rear 5 pinion planetarys, 29 duel cage sprag, pump, input drum, sunshell, ect,ect..
What ever could be done to prevent future failure so it definitely isnt anything with the transmission..


I guess this slight production tolerance is to much for my application or maybe it would have worked with a car that has 20-30,000 miles of wear on it I don't know,
I just know that it will not work on my car..
The driveshaft is a nice quality piece everyone says it looks really good and I researched it to death on here without reading about a single issue with them..
If there is a problem it usually happens with my car it has fought me the entire way of modifying it
My girlfriend calls it Christine for a reason hehe

stoverz28

iTrader: (8)

Did your tranny have enough fliud in it to keep things lubricated back there? I also usually put some grease around the yoke where the seal would sit, just to help things out a little more.

And for what its worth mine was a PITA to get in, had to use a rubber mallet like Bob explained.

9000th01ss

iTrader: (10)

I'd take the tail housing off and hone the bushing with a brake hone.
It's not uncommon for bushings to have a smaller ID and require honing, or just stuff the shaft in and let it wear itself, that usually works.

Edit: I find it hard to believe the seal burned out from heat and the bushing is fine. Usually the bushing will spin. After the bushing spins, the bore in the housing gets tight and every bushing you put in it afterwards will be tight.

NJ 2002 Z28

Yeh I am not going to go through the hassle of customiing things in order to be able to use the drive shaft..
It is going to get returned as soon as EPP arrange's for it to be picked up..
And I will use my stock driveshaft until the tracks open back up in the Spring then I will probably go with a Spohn driveshaft...

Firehawk441

iTrader: (41)

That sucks. I'm sure EPP will work everything out.