[possible prolapsed tailshaft spline on GMS S-15 truck
 

I have an 82 GMC S-15, v6 2.8L, 2 wheel drive, long wheelbase.

After 140,000 or so miles, one of the driveshaft U-joints disintegrated,
and the subsequent flailing around destroyed the equally old driveshaft
support bearing and cushion (it's a 2 piece driveshaft).

Took it out, and had the U-joints replaced, and pressed on a new support
bearing & cusion assembly. But, now, when I try to put everything back on
the truck, I insert the transmission yoke in, and at the other end of that
driveshaft segment, the support bearing is too far aft to bolt into its
postion on the crossmember, by about an inch. I compared with the old parts,
and everything is the same dimensions. I notice, that the splined shaft that
pokes out of the tailshaft (that receives the slip yoke on the front of the
driveshaft) is poking out of the end of the tailshaft housing by about an
inch ... haven't seen many of these - all my other driveshaft fixes have
been on manual trans cars - is that protrusion normal? I'm thinking not...if
not, is sorting it out a job for an amateur, or should I have it towed to
the transmission shop? Anyone seen this problem before?

Lee K. Gleason N5ZMR
Control-G Consultants

[possible prolapsed tailshaft spline on GMS S-15 truck
 

How are the engine or tranny mounts? That implies to me the engine has
shifted back.... Maybe the cause of the u-joint failure?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
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"Lee K. Gleason" wrote:
>
> I have an 82 GMC S-15, v6 2.8L, 2 wheel drive, long wheelbase.
>
> After 140,000 or so miles, one of the driveshaft U-joints disintegrated,
> and the subsequent flailing around destroyed the equally old driveshaft
> support bearing and cushion (it's a 2 piece driveshaft).
>
> Took it out, and had the U-joints replaced, and pressed on a new support
> bearing & cusion assembly. But, now, when I try to put everything back on
> the truck, I insert the transmission yoke in, and at the other end of that
> driveshaft segment, the support bearing is too far aft to bolt into its
> postion on the crossmember, by about an inch. I compared with the old parts,
> and everything is the same dimensions. I notice, that the splined shaft that
> pokes out of the tailshaft (that receives the slip yoke on the front of the
> driveshaft) is poking out of the end of the tailshaft housing by about an
> inch ... haven't seen many of these - all my other driveshaft fixes have
> been on manual trans cars - is that protrusion normal? I'm thinking not...if
> not, is sorting it out a job for an amateur, or should I have it towed to
> the transmission shop? Anyone seen this problem before?
>
> Lee K. Gleason N5ZMR
> Control-G Consultants
>

[possible prolapsed tailshaft spline on GMS S-15 truck
 

"Lee K. Gleason" > wrote in message
...
> I have an 82 GMC S-15, v6 2.8L, 2 wheel drive, long wheelbase.
>
> After 140,000 or so miles, one of the driveshaft U-joints disintegrated,
> and the subsequent flailing around destroyed the equally old driveshaft
> support bearing and cushion (it's a 2 piece driveshaft).
>
> Took it out, and had the U-joints replaced, and pressed on a new support
> bearing & cusion assembly. But, now, when I try to put everything back on
> the truck, I insert the transmission yoke in, and at the other end of that
> driveshaft segment, the support bearing is too far aft to bolt into its
> postion on the crossmember, by about an inch. I compared with the old
parts,
> and everything is the same dimensions. I notice, that the splined shaft
that
> pokes out of the tailshaft (that receives the slip yoke on the front of
the
> driveshaft) is poking out of the end of the tailshaft housing by about an
> inch ... haven't seen many of these - all my other driveshaft fixes have
> been on manual trans cars - is that protrusion normal? I'm thinking
not...if
> not, is sorting it out a job for an amateur, or should I have it towed to
> the transmission shop? Anyone seen this problem before?
>
> Lee K. Gleason N5ZMR
> Control-G Consultants

Yes the output shaft of the tranny sticks out a bit.

making a couple of assumptions here (a dangerous thing to do I know)
you have installed the drive shaft on the spline and hooked the rear u-joint
to the rear end and the over all length appears ok, except the center
support mounting holes aren't lining up. Is it possible the bearing wasn't
pressed on far enough, or that it is the wrong bearing? Or it was pressed
on incorrectly and the retention ring kept the assy from pressing on far
enough?
Timken part number HB88107E

You say compared new to old, by eyeball or did you measure?

Whitelightning

[possible prolapsed tailshaft spline on GMS S-15 truck
 

"Mike Romain" > wrote in message
...
> How are the engine or tranny mounts? That implies to me the engine has
> shifted back.... Maybe the cause of the u-joint failure?
>

There is less than an inch between the front of the tranny mount and the
rear of the tranny pan. Shifting that far would result in a hole in the pan
(first hand knowledge here, daughter wrecked one of my S-10s, drove water
pump through timing cover, shoved drive train back, flange on crossmember
for mount did a nice job on the pan). To remove the pan requires unbolting
the mount from the tranny and then jacking the tranny up, and/or remove the
crossmember.

Whitelightning

[possible prolapsed tailshaft spline on GMS S-15 truck
 

"Whitelightning" > wrote in message
news:gvycf.22037$Ny6.297@trnddc06...
>
>d> making a couple of assumptions here (a dangerous thing to do I know)
> you have installed the drive shaft on the spline and hooked the rear
u-joint
> to the rear end and the over all length appears ok, except the center
> support mounting holes aren't lining up. Is it possible the bearing wasn't
> pressed on far enough, or that it is the wrong bearing? Or it was pressed
> on incorrectly and the retention ring kept the assy from pressing on far
> enough?
> Timken part number HB88107E

Yah, measured 'em and they are the same. But, I'm starting to think that
maybe the problem happened when I had the transmission worked on a couple of
months back - now that I think about it, the old center support was all torn
up, I assumed the disintegrating u joint did it, but maybe being forced into
mis-position by the smooth apes at the transmission place is what destroyed
it, and maybe the mounting spots were misaligned somehow by them...time to
crawl back under and study it some more. Thanks all for the ideas.

Lee K. Gleason N5ZMR
Control-G Consultants

[possible prolapsed tailshaft spline on GMS S-15 truck
 

"Lee K. Gleason" > wrote in message
...
>
>
> Yah, measured 'em and they are the same. But, I'm starting to think that
> maybe the problem happened when I had the transmission worked on a couple
of
> months back - now that I think about it, the old center support was all
torn
> up, I assumed the disintegrating u joint did it, but maybe being forced
into
> mis-position by the smooth apes at the transmission place is what
destroyed
> it, and maybe the mounting spots were misaligned somehow by them...time to
> crawl back under and study it some more. Thanks all for the ideas.
>
> Lee K. Gleason N5ZMR
> Control-G Consultants
>
>

Is there a resolution yet?
Whitelightning