When did Jaguar begin using the four speed automatic behind the V-12 ? Is there a worthwhile benefit in going with this trans versus the TH400 ? Thanks very much in advance as this might impact a buying decision.

 

The 4 speed 4L80E was introduced along with the 6 litre V12s.....circa 1994 on the XJS. Someone here will know that exact change point. None of the 5.3 V12 used it.

The 4L80E is a TH400 with the addition of and o'drive 4th gear and electric shifting. The primary advantage is the o'drive 4th gear allows more agressive differential gearing, 3.54 versus 2.88.

That 3.54 gearing really improves the performance of the car. The extra power of the 6.0 engine doesn't hurt, either

Cheers
DD

 

The standard (as opposed to XJR-S) 6 litre came in with the introduction of the big plastic bumpers. This was at VIN 1881105 which was in April 1993. All the 6 litre XJS from this point use the 4L80E

So if you get a 4L80E, you also get a later 6 litre XJS which (just in my opinion!) is a better car anyway.

Paul

 

One suggestion I have is to use the synthetic appropriate Dexron ATF in these GM sourced trannies. In my experience the transmissions last longer due to synthetic braking down at higher temperatures when compared to conventional ATF.