So I have a 95 blazer with the computer on the coolant resivoir, obd1.5. I had the same problem about 5 months ago & replaced it with a used trans. I lost 3rd & 4th gear. Now it happened again. I can drive fine as long as I manually shift 1st and 2nd. I'm confident I need to rebuild it. I have plenty of mechanical skills & I'm not terribly unfamiliar with the innards of an auto trans, but I'm unsure what my options are as far as rebuilding it. I know this was a goofy year for this transmission and I want to know if there is a particular rebuild kit for this year, what shift kit I can use, and what upgrades I can make. Any help would be great.

 

You can install a shift kit if you want but really no upgrades are necessary. The only thing I would suggest is going to either the "Beast" sunshell or the sunshell out of a '00+ 4L65e. These will require the use of bearings insteal of the plastic washers. A bit of research is required so you know what you need exactly. Either way it will probably run you around $40. As far as a rebuild kit, it pretty much depends on what you want to spend and how you drive. The 4.3 is no monster so any kit should work. If you were making more than 250hp I'd have a different answer. You can upgrade to a .5" boost valve which increases line pressure to increase clutch pack holding power. However a shift kit may include that.

The only real problem is figuring out why the transmission failed in the first place. Mine got water in it which was evident by a few rusty parts and the dipstick which was just about rusted in half. So I suffered from the 'water down the dipstick' issue. Depending on the mileage(200K or more) there are a few other possibilities but the 3+4 cluch pack is very snesitive to pressure loss in these transmissions so running low on fluid or an internal loss from a worn valve or valve body separator plate would do it.

Good luck.

 

Go with 'The Beast' sunshell. Costs about the same as the newer GM piece, but still is FAR superior. I couldn't believe the difference between the stock sunshell in my '04 Tahoe & 'The Beast' that I installed.

If you are considering doing this yourself, you'll want to invest in the ATSG manual for the 4L60E. Search on youtube as there are tons of videos, including professional ones showing the various steps of rebuilding a 4L60E.