Hello Group,

I recently purchased a 1982 VH commodore (202 engine/trimatic/full LPG).

The transmission (trimatic "L L") is slipping between gear changes.

I have a workshop manual and purchased a new modulator and transmission service kit.

The original modulator was leaking fluid slightly so I replaced itwith the new one and checked the vacuum line and there is no leaks or blockage. Unfortunately, this made no difference. Still slipped between 1st & 2nd (revs out on change) and slow to go into 3rd.

After removing the oil tray I was happy to see no metal residue. The servo band housing had a 3-4mm layer of grey sludge at the bottom, but no metal, and there was no metal in the filter, so I think that's a good sign.

I've adjusted the band as per specs as best I could. Unfortunately the torque wrench I have is a bit heavy duty so it was hard to get accurate. I tightened to 4.7nm (3.3ftlb) and backed off 4 1/2 turns.

This definitely has made an improvement - If the engine is not under too much load it now changes smoothly between 1st & 2nd, still quite a bit sluggish going into top gear though. Under load, it will "flare" between 1st & 2nd but not as bad as before.

* Should I tighten the band further? it seems this would be the way to go. If the band is overtightened what would the effects be?

* Or is the modulator playing a role here - I noticed that the new
modulator has an adjustment screw on the hose side. (the previous modulator didn't have one, or was removed) Should it be adjusted?

Also, one thing that still bugs me is that if the shift is put into 2nd, it will change between 1st & 2nd fine. - Why is this the case.

Your advice would be appreciated.

Steve.

Steve when you removed the servo cover and found the sludge in the bottom,did you notice a broken piece of plastic about the size of a match head?
I cant remember when/which model tris had them but the plastic dump valves were a common problem that broke

Hi Nathan,
Your probs sound a bit more dramatic than mine, and yes, it would be good to know if it's something that can be adjusted - or if it's rooted.

Thanks for your info Mario,
I'm pretty sure there was nothing apart from the sludge in the servo

One other thing I forgot to mention is that this morning (which was a lot cooler than the last few days) the transmission was quiet smooth - didnt "flare" as much until it got warmed up (approx 15mins)

This could be a clue to someone who is experienced

vh commodores never came out with a 186. the 186 ceased production in 1969-70

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In cubes we trust.

173. The original clutch material isnt very good on the trimatics. maybe thats causing your problem. its very hard to diagnose a mechanical problem over the internet. sorry

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In cubes we trust.

Yeah Boom - true, but I was hoping that someone with experience with trimatics might be able to point me in the right direction.

I certainly won't be taking it in to an auto specialist (not yet anyway) until I'm petty sure what the problem is (or isn't

One point though - if it is the clutch material, why didnt I find any ground metal? I was surprised that there wasnt one bit.
Perhaps the evidence was cleaned away in a previous service?
hmmmmmmm.
Steve