'94 K2500 Transmission slip...

[The Munz]

Noticed slight slip/delay during downshift at less than 5 mph up a steep paved grade. 340K on vehicle and I assume on trans. What's the average life of this generation transmission? Ball park $$ to have it rebuilt? While trans is out, is it sound to install new rear main seal? Or too many miles on thrust bearing to matter? Oil pan is creased, so time to replace that and leaky oil filter adapter housing o-rings etc. as well.
Thanks!!

[Robyn]

Hi

With that amount of miles.....Yes....a complete overhaul on the tranny.....Average life span.....subjective.

If they are taken care of well.....Vs not so much.......340K is a really good run......

Get it overhauled before it eats itself up....The 4L80 does not like junk running through the valve body (Aluminum)

Definitely replace the rear main seal while the tranny is out .......If it is leaking a bigger yessssss.

Get all the goodies fixed while you are in there........

As far as cost....Depends on many things.....If the tranny can be saved with seals, clutches and such.....Definitely a fresh converter......Usually bushings and thrust washers.

Shift solenoids for sure.

Get referrals on a good local shop that has a good track record and knows what they are doing.....Stay away from the big box shops.......

[arveetek]

I got 375K out of mine before the torque converter started slipping and wouldn't stay locked up. I pulled the transmission myself and had it rebuilt locally by a reputable shop. It cost me $1600 a little over a year ago.

NOTE: make sure you order the correct torque converter! The diesel uses the low stall converter; most transmission shops don't realize this and will get you the higher stall torque converter. A lot of the parts listings that the shops use only list one torque converter.

I had the transfer case gone through at the same time. It wasn't that expensive, and gave me peace of mind with all new seals.

Yes, replace the rear seal while you're at it. There's no reason not to do that.

Casey

[The Munz]

OK, Any idea if rear main seal is one-piece, or two piece?
Thank You as always!

[a5150nut]

if your up to tackling the transfer case your self drivetrain.com is excellent for parts and would have the correct converter for your trans. Those guys even answer the phone on weekends and are very knowledgeable and helpfull.

[arveetek]

OK, Any idea if rear main seal is one-piece, or two piece?
Thank You as always!

Factory 6.5L in 1994 would be a one-piece seal. You would HAVE to remove the transmission to replace it, so it's definitely worth doing with the transmission out of the way anyway.

Casey

[More Power]

Factory 6.5L in 1994 would be a one-piece seal. You would HAVE to remove the transmission to replace it, so it's definitely worth doing with the transmission out of the way anyway.

Casey

This would also be a good time to deal with leaky engine oil cooler lines, especially if the vehicle is on a lift.

Secondarily... the factory 4L80-E came from GM with a great pan gasket. It was made from aluminum with an o-ring seal. This gasket does not need to be replaced - it's re-usable. Rebuilders usually toss it... and install something less good.