95 Jimmy - 4L60-E ground upgrade/recall TSB??

Hi there,
Have any of you heard of an upgrade or recall for GM's 4l60-E transmission that speaks on a ground upgrade? I was speaking with a tech who mentioned that I should have this done or risk repeated
possibilities of clutch failure. Seeing as my clutches checked out after about 50k km with less than 2 years on a full rebuild, I thought I'd ask here.

Thanks,
Andrew.

Andrew wrote:
> Hi there, Have any of you heard of an upgrade or recall for GM's
> 4l60-E transmission that speaks on a ground upgrade? I was speaking
> with a tech who mentioned that I should have this done or risk
> repeated possibilities of clutch failure. Seeing as my clutches
> checked out after about 50k km with less than 2 years on a full
> rebuild, I thought I'd ask here.
>
> Thanks, Andrew.
>
>

\Nothing I have heard of or seen says anything about a ground upgrade
with regards to clutch failure. Considering that the clutches are
applied hydraulically through the control solenoids that are grounded
separately in the first place I can't see where it would do anything.

I would say the problem was not related to the ground but may have been
a bad part or the rebuilder just had a bad day. Or they didn't check the
valve body for wear.

Steve W.
Near Cooperstown, New York

Thanks Steve! Apparently the valve body is fine but the 2-3/3-4 clutches and steels plus the forward sprag are gone. I think it might have been my fault for the mostpart that this box failed as a VERY
stiff spring was requested by me. The builder originally told me that the shift was likely too aggressive for a DD and would cause me to get whiplash, failed mounts and likely problems down the road.
I stuck it out as the comsumer knowing better and tore 2 mounts and ended up doing internal damage MAYBE due to this. I haven't mentioned this ground issue to my builder but I did hear about it
from someone else who builds a large number of these transmissions. He is sending me the wiring upgrade/ground issue details shortly and then likely I will know more. The long and short of this is that
I will end up getting the truck (well... Jimmy S15) back in a day or so to the tune of $1200 CDN. I will be going considerably more easy on her this round, getting the more sensible spring put into the shift
kit and crossing my fingers. The next big problem I have with this truck will have me dumping it in a heartbeat and looking for another project vehicle.

Thanks again,
Andrew.

>
>\Nothing I have heard of or seen says anything about a ground upgrade
>with regards to clutch failure. Considering that the clutches are
>applied hydraulically through the control solenoids that are grounded
>separately in the first place I can't see where it would do anything.
>
>I would say the problem was not related to the ground but may have been
>a bad part or the rebuilder just had a bad day. Or they didn't check the
>valve body for wear.
>
>Steve W.
>Near Cooperstown, New York
>
>

I think we figured it out. I believe I am 100% to blame. I think either
when I replaced a line on the oil cooler or put in a new rad, I kinked the
transmission line from the return side of the cooler. It looks like the
'mild kink' got considerably worse as time went on... The tech thinks that
this starved the transmission and burned up the clutches. He pulled that
line and replaced it free of charge also. The truck seems to shift very
nicely now (I would suspect it would after a damn near repeat full rebuild).
I guess I need to be more carefull!!! I've never screwed anything up this
badly before but there's a first time for everything.

Hose to replace = $15
Cost of transmission repair = $1200 CDN before taxes
Cost of my ignorance = priceless...


Andrew.


On 27/11/08 12:08 AM, in article ,
"Andrew" > wrote:

> Thanks Steve! Apparently the valve body is fine but the 2-3/3-4 clutches and
> steels plus the forward sprag are gone. I think it might have been my fault
> for the mostpart that this box failed as a VERY
> stiff spring was requested by me. The builder originally told me that the
> shift was likely too aggressive for a DD and would cause me to get whiplash,
> failed mounts and likely problems down the road.
> I stuck it out as the comsumer knowing better and tore 2 mounts and ended up
> doing internal damage MAYBE due to this. I haven't mentioned this ground
> issue to my builder but I did hear about it
> from someone else who builds a large number of these transmissions. He is
> sending me the wiring upgrade/ground issue details shortly and then likely I
> will know more. The long and short of this is that
> I will end up getting the truck (well... Jimmy S15) back in a day or so to
> the tune of $1200 CDN. I will be going considerably more easy on her this
> round, getting the more sensible spring put into the shift
> kit and crossing my fingers. The next big problem I have with this truck will
> have me dumping it in a heartbeat and looking for another project vehicle.
>
> Thanks again,
> Andrew.
>
>>
>> \Nothing I have heard of or seen says anything about a ground upgrade
>> with regards to clutch failure. Considering that the clutches are
>> applied hydraulically through the control solenoids that are grounded
>> separately in the first place I can't see where it would do anything.
>>
>> I would say the problem was not related to the ground but may have been
>> a bad part or the rebuilder just had a bad day. Or they didn't check the
>> valve body for wear.
>>
>> Steve W.
>> Near Cooperstown, New York
>>
>>
>

the valve body should be replaced with any rebuild

"Steve W." wrote:

> Andrew wrote:
> > Hi there, Have any of you heard of an upgrade or recall for GM's
> > 4l60-E transmission that speaks on a ground upgrade? I was speaking
> > with a tech who mentioned that I should have this done or risk
> > repeated possibilities of clutch failure. Seeing as my clutches
> > checked out after about 50k km with less than 2 years on a full
> > rebuild, I thought I'd ask here.
> >
> > Thanks, Andrew.
> >
> >
>
> \Nothing I have heard of or seen says anything about a ground upgrade
> with regards to clutch failure. Considering that the clutches are
> applied hydraulically through the control solenoids that are grounded
> separately in the first place I can't see where it would do anything.
>
> I would say the problem was not related to the ground but may have been
> a bad part or the rebuilder just had a bad day. Or they didn't check the
> valve body for wear.
>
> Steve W.
> Near Cooperstown, New York

Even if a brand new one was put in less than 20k km ago on a new
transmission? There was no debris or anything. The clutch packs were
starved for oil because of a kinked line beside the oil cooler under the
hood. If hindsight really were 20/20 I would have never had this problem.



Thanks,
Andrew.



On 29/11/08 11:09 AM, in article , "man of
machines" > wrote:

> the valve body should be replaced with any rebuild
>
> "Steve W." wrote:
>
>> Andrew wrote:
>>> Hi there, Have any of you heard of an upgrade or recall for GM's
>>> 4l60-E transmission that speaks on a ground upgrade? I was speaking
>>> with a tech who mentioned that I should have this done or risk
>>> repeated possibilities of clutch failure. Seeing as my clutches
>>> checked out after about 50k km with less than 2 years on a full
>>> rebuild, I thought I'd ask here.
>>>
>>> Thanks, Andrew.
>>>
>>>
>>
>> \Nothing I have heard of or seen says anything about a ground upgrade
>> with regards to clutch failure. Considering that the clutches are
>> applied hydraulically through the control solenoids that are grounded
>> separately in the first place I can't see where it would do anything.
>>
>> I would say the problem was not related to the ground but may have been
>> a bad part or the rebuilder just had a bad day. Or they didn't check the
>> valve body for wear.
>>
>> Steve W.
>> Near Cooperstown, New York
>