My neighbor is in a bit of a bind. He owns an '88 Chevy 1/2 ton standard cab, short bed. It has a 305V8 and a 3-spd automatic. He blew his trans and is in need of a new one. He was told it was a TH375, and proceeded to purchase one from a local company. He handed in his core up front (big no-no) and waited for his replacement trans. Firstime they shipped a Th400, second and third time, they shipped a TH375 but without the electronic speed sensor tailshaft, so it won't work. They ended up giving him $120 for his core because now they can't seem to find it. He came to me after the fact and I'm trying to help him out (he is in a wheelchair to boot, was in a major motorcycle accident 3 months ago).

So, a couple questions. I've never heard of a TH375. Is there such a thing? What's the dealio with the speed sensor, should he have salvaged some parts off his core to make it work? Recommend hitting the junkyard to get those essential parts? Can a new trans be purchased with required tailshaft to work in his truck (he can't seem to find one locally yet). Can a th350 or th400 be put in and if so, what year/vehicle/configuration will work with his 88? All in all, he realizes he should have just had it rebuilt, but will do just about anything to get a new one before winter arrives. Any help you guys can give me is greatly appreciated!

Thanks,
Chris

You didn't mention if this was a 2 or 4 wheel drive.

Anyway, 2wd would be easy, nearly any trans would work, but I puzzles as to why this truck had a three speed, it should have had a 700R4, or 4L60E, both overdrive fourspeeds. Seems fishy, but TH350 swaps were really common on the earlier 700R4's because people thought the 700 was just too expensive to rebuild. Some of the first few years of the IFS trucks had TH400's, but I've only seen a couple, and those were of questionable origin and could have been swapped. The TH375 is a light duty version of the TH400, used in the early seventies, and in some Buick Olds Pontiac applications into the early eighties. The TH475 was a super heavy duty version of the TH400 used in motorhomes and heavy trucks.

i tooam not sure why it has a 3 speed. it shiuld have a 700r4. if it was me i would just have my old trany rebuilt. but in your case i would look for a 700r4 and utilize the overdrive. but if you want to keep it simple i would just find a wrecked truck with lo miles at a junk yard and pull her out. or if all els fales take her to a trany shop and let them do it all!

Originally posted by 4Bangler
You didn't mention if this was a 2 or 4 wheel drive.


Yea, it's a 1988 2x4 Scotsdale. I just got back from his house. I grabbed the VIN and all the RPO codes to see what it came with stock. Here they are...

A01 A52 B74 B84 C5G C95 D45 E63 F59 GMC GU4 J50 K99 L03 MX1 M40 NA5 N41 N67 SLM UK4 U37 U73 VB3 VG3 VK3 V73 XEV YD3 YD5 YD6 YEV ZEV ZY1 Z53 Z62 18U 6WN 7WN 82C 82I

Any help is appreciated...

Chris