Transmission Problems

The place to discuss problems and routine maintenance questions and tips. This is for topics that are specifically diesel-related.
jaredvd
Regular Member
Posts: 99
Joined: Mon Sep 24, 2012 12:16 pm
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Isuzu vehicle(s): 86 spacecab with 82 diesel swap

Transmission Problems

Postby jaredvd » Sat Apr 12, 2014 2:27 pm

I did the transmission upgrade about 6 months ago, and have been having some intermittent problems.

At times the transmission shifts fine, but other times it just wont go into gear. It often grinds when shifting from 2nd to 3rd, and I can almost never downshift it from 4th to 3rd.. but can downshift it from 4th to 2nd. Double clutching sometimes helps, but often doesnt.

I figured it was just the clutch cable/firewall which was rigged up with a piece of rebar and a nail.... So I fixed that all up nice, and replaced the cable, but the truck still has problems. The strange thing is it seems to work better, and be more intermittent. So now the truck will drive and shift thorough the gears.. 3rd still doesn't feel as good as the other gears, but it'll shift in fine... then all of a sudden it'll grind going into 3rd and and feel stuck going into any other gears. Perhaps it only happens when the trans is hot? I was thinking the syncronizers.. but it doesn't make sense that all of a sudden it just wont go into any gear. Sometimes i have to literally come to a stop, put it into first, then keep on going. At these times Double cluching, rev matching and everything else seems to do nothing... I have to stop the truck.

Then there are other times where the truck will downshift and drive just fine.

Also now when I start the truck up sometimes I can't get it into reverse... this was never a problem before.

The only thought is perhaps i messed up the pilot bearing and at times it's just getting stuck? I hope not. I'm confused now as the clutch cable seemed to help the problem, but not fix it. I've tried to adjust it a bunch of times.

Where should I go from here?
86 spacecab with 82 diesel swap