My mechanic finished an overhaul on the engine (4.2l) and now has problems with the transmission. The car sat for two years and was only started weekly. The transmission will not upshift to second. The car never had this problem before sitting. Can someone list the most likely culprits. I would rather not take this to a transmission specialist or rebuild, but will if necessary. The car is a 1984 series 3 VDP.

 

I'd try draining the trans fluid and putting in fresh filter first. Some good details in this thread:

https://www.jaguarforums.com/forum/x...-shift-146523/

 

On re-installation of the engine I wonder if the shift valve cable (the one that goes to the throttle body) somehow became mis-adjusted? Or damaged?

The adjustment is rather critical and technically must be made with a pressure gauge but the shop manual shows an alternate method....which is hard to explain without pictures.

I'll see what I can come up with if you don't have a manual

Cheers
DD

 

The mechanic said the shift valve cable was the first thing he checked. He has not, however, replaced the filter yet. There is a minor leak there. He is going to replace filter today but said repeatedly flushing the system will cost 100/flush, so it's cheaper to rebuild. A local transmission shop said they would rebuild it, if necessary, but that the problem is likely either with controls or vacuum system. Their price was 300 plus parts. Any help is appreciated.

 

If you have the ability, inclination, time, and facilities you could try some DIY remedies which require getting into the transmission a bit.....

Stuck governor, perhaps?

Gunked-up valve body?

Hopefully someone will come along with some easier and more palatable ideas but I'm thinking a visit to the transmission shop is in your future.

Cheers
DD

 

I would suspect the governor - had the same issue on my old silver Six - but a gunked up valve body could cause it too. Both issues can be remedied without removing the gearbox but it is messy work.

To check the valve body, you need to drain the ATF and remove the sump.

The governor can be checked without draining the ATF by elevating the car's rear end; the governor is inside the extension housing of the gearbox so you have to disconnect the speedo transmitter, prop shaft, and rear gearbox mount.

Three hundred bucks plus parts isn't bad to overhaul the box. I rebuilt one myself and the kit was around $120.

 

1st, Check the front brake band adjustment,
2nd check the front servo for leaks and
3rd check the pipes that are in the valve body hav'nt fallen out.
if your getting first and reverse the line pressure is more than likely o.k and also the clutches and release spring is good also which are the usual terminal failures with the T66.