86 Chevy 1/2 ton tranny trouble?

chevrolet

#1

Hi all.



A friend of mine has an 86 Chevy 1/2 ton, all origional. His problem is that the truck is “slow” going into reverse, but once there, feels “solid”. I haven’t personally looked at the truck, and am not sure what his concept of “slow” is, but if anyone has a “I know what he’s talking about” solution, I’d greatly appreciate it.



I understand there’s probably not enough information to determine the cause, but it doesn’t hurt to try.



Thanks


#2

No, but I can ask questions you may (or may not) know the answers to:

Mileage?
Service history (specifically the transmission)?
&nbsp&nbsp&nbsp-last filter change?
&nbsp&nbsp&nbsp-last fluid change?
Has the fluid level been checked?
Are there any leaks he can see (and has he looked)?
Puddles under the truck where he normally parks?


#3

Don’t know the milage.

He did mention that he changed the filter and serviced the fluid, with no leaks noted. He doesn’t drive the truck often, but said that after the servicing, it seemed to do better. Not fixed, but less noticable.

As far as a persistent leak (puddles undr the truck), I don’t know. Going by your questions, it seems this type of problem is fluid (or lack there of)oriented. Would this be a good place to start looking?


#4

No. If the fluid level is good you are usually looking at either a boost valve in the pump assy or an internal leak issue in the reverse input clutch.

transman


#5

Yup…whatever transman says. I yield.

(providing the fluid is at the right level)…


#6

Is the boost valve, pump assembly, or the reverse input cluctch something that can be trouble shot and replaced without a complete overhaul?


#7

A line pressure/line rise test by a trans shop should narrow down the problem. It would be a waste to remove and disassemble a transmission that old and just replace a piston seal or valve.

transman


#8

Thanks for all your help, I’ll relay the messages and hope for the best.