Thread: Any auto transmission experts

1; The 1988 box had a very poor shift pattern, changing up way too early when pulling away from a standing start. This was much improved in the 1991 model. Would a swap of the valve bodies give the old box the shift characteristics of the later box?

POD was the 1988 a 3.5 or 3.9 (3.9 only came in 89 model) . If a 3.5 it is a 2HP22 not a 4HP22 like a 3.9 trans and theoretically is too weak for a 3.9.
The shift pattern depends on the setting of the kickdown cable. The more showing the higher the shifts.
AFAIR the 2HP22 torque converter locks up at about 60KMh not 85kmh like a 3.9.
Regards Philip A

g'day Philip,
The 88 was a 3.5 but both boxes are definitely 4hp22. I had much discussion on the old forum at the time of rebuilding the transmission, as well as with the rebuilder. There was something about the shift pattern in the earlier ZF boxes where they change into 2nd almost immediately upon taking off and 3rd very early also, this causes a lag which makes the driver give more throttle which makes the box change down which makes you back off which lets it change up again........ the kickdown cable adjustment notwithstanding. Along with the bloke who did the reco, we tried adjusting it out in the kickdown but that led to too much kickdown without much change in the low-throttle shift pattern. The 1991 box- prior to it's death- had a much more sensible shift pattern.
The convertor in both vehicles locks up bang on 80km/hr. I had a low-stall convertor supplied along with the reco, made a surprising amount of difference to engine braking.
I think I might just take both boxes in to the rebuilder and get him to give the reco one a look over, as well as maybe swap valve bodies. Don't want to be doing this job again anytime soon.
I've discovered I need to fit the speedo drive gear from the BW into the LT230 whilst I have it out also. I've already confirmed it will fit.

the early box has more than just slight valve body differences, iirc the cam shape for the kickdown cable is a different profile, the governor is a different spec (weight) these 2 causing the early changes, and the converter from memory is also slightly different where it engages at the pump. I would either fit the early box in its entirety, or repair the other. Don't try and mix and match the 2.

JC

Hi I'm with JC. The early type 1043 010 332 had a very early shift, very useful parts for a diesel conversion, the gov is different, kickdown cam profile is different, hysterisis spring is different on and on. The next version type 1043 010 593 fitted to the 3.5 efi was a little better, the 1043 010 699 was fitted to the 3.9 and had a decent shift pattern. At least change the kick down cam and the gov for one from the 699 Regards Ian Ashcroft