new member and question on automatic transmission

[uras]

Good day everyone. My name is Vince. I own a 1974 Jaguar XKE and a 69 420G. I inherited the XKE from a friend who passed away many years ago and I have undertaken the restoration with her vision in mind. I was the only one she trusted to complete the restoration on her 'baby' and so I had an obligation to complete this no matter the time or money. The 420G I picked up from a field and it had been neglected for a decade, and even though it was in really rough shape it was a complete original car, and I could not bear for it to go to the graveyard. The smell of mice feces and urine was almost enough to put me off but I had to save the 420G.

I have problem with the automatic transmission on the XKE, and I am hoping someone may be able to shed light on the issue. As a little background, my friend who passed away was the original owner. It is a complete number matching vehicle including the original bill of sale. She had a binder with every invoice in it no matter how small, including taxi receipt to pick up the car. It was an order by her with what options she wanted including the 3 speed automatic, AC, radio, and colour keyed hardtop. It has the original hardtop in dark blue. Everyone says that the factory only delivered the hardtop in black. But my original bill of sale shows matching colour hardtop from factory. Maybe the dealer painted it afterwards, but when the hardtop was sanded down, it was only the original layer of dark blue and no black underneath it. Also not sure if the dealer would have had time to repaint it, as the records show it come in and she picked up the next day. Not that it matters but was curious as the 'experts' insist the hardtop was only in black. I kept everything original with the exception of having the 1974 bumper/overriders installed (retained the ugly 74 bumpers/overriders), and had a better sounding exhaust system installed.

I had a bumpy road finding trades to do the mechanical work. One shop started the restoration. I was not happy with their progress, and it just got to the point where i was bankrolling their other projects and mine was not being completed on a timely basis. As such, I went to another shop. The next shop has been great, even though they 'misplaced' the original console surround for the radio and the original radio itself. However, the first shop had the AT rebuild and so i/shop presumed that that was fine and had it installed when the rebuilt engine went in.

Well, lo and behold, the transmission does not shift from 2nd to 3rd. It shifts from park to reverse and drive normally. It shifts from first to second normally. It does not shift from 2nd to 3rd at all, even at close to maximum RPM. The shop had it taken to a transmission shop, and their recommendation was to drop the AT to overhaul it again. You all know how much work and time and $ that is, especially when the engine is running so well and has been set up.

If the engine has to be pulled out again, than that is what will need to be done. First though I thought I would check with you folks if there is anything you may recommend first before proceeding with the removal of the driveline.

Other than the AT issue, all that is left is to have new correct period tires installed, and the car can be enjoyed. It has been a long 5 years but now at the end stage of the restoration.

Attached are three pictures. The first one is many years ago before the restoration, and the second and third ones are with the current restoration. The colour is the same, dark blue, just the lighting makes it look darker.

[uras]

oops....meant to say bumpers/overriders changed to 1972 style. my fat fingers do not follow the brain!

[christopher storey]

Well, lo and behold, the transmission does not shift from 2nd to 3rd. It shifts from park to reverse and drive normally. It shifts from first to second normally. It does not shift from 2nd to 3rd at all, even at close to maximum RPM. The shop had it taken to a transmission shop, and their recommendation was to drop the AT to overhaul it again. You all know how much work and time and $ that is, especially when the engine is running so well and has been set up.

Nice looking car Vince . Several questions ... 1.When the transmission engages Drive/Reverse is it "bumpy" in doing so ? 2.Is the 1-2 shift smooth or bumpy ? 3.Does the 1-2 shift occur at higher speed if the throttle is opened wider or is it always at the same road speed ? 4. Have you tried backing off the throttle to a cruise level at say 45 mph in 2 , and if so what happens?

I am not very familiar with the Model 12 BW transmission , but I believe that it is very similar to the Model 8 with the addition of barometric compensation, and if that is so I would check first of all that the kickdown cable is operating smoothly and is - in particular - not too short - if it is, bumpy changes are nearly always present . If that is clearly not the problem then the next check is the manual selector linkage, as this could be causing the operating lever on the box to be failing to engage in the detents properly.If there is any doubt about that, it may be worthwhile disconnecting the linkage and engaging drive by the box operating lever, ( IIRC this is accessible through the left side of the tunnel ) and then seeing if the upshifts occur differently ( of course, extreme care is needed to ensure that the vehicle does not move off unexpectedly ) . If neither of those problems are present, then the fault is almost certainly hydraulic, and the most obvious cause would be the 2-3 shift valve and/or its plunger sticking . AFAIK, these, the various filters , the oil tubes, and the governor assembly itself, are all accessible from under the car with the oil pan off. It is many years since I have done so, but I recall it was not too difficult to remove the valve body using an impact screwdriver to undo the screw fasteners. Best of all is to find a "travelling mechanic" who is familiar with the BW12 box and can look it over and check it in the car with pressure gauges where necessary


I hope this is of some help. The subject is not at first sight one for the faint-hearted, but in fact autoboxes are really only logic circuits controlling an epicyclic gear train , and in many ways are simpler than manual boxes. I certainly would not be having the box out before having completed all the checks one can do with it still in the car. For a general idea, have a look at the Model 8 section of the 4.2 manual in the knowledge base on this site : here's a link to it https://www.dropbox.com/s/q6t23z6uhab78 ... n.pdf?dl=1

[uras]

Thank you for your feedback Christopher.

When I test drove it, it did feel like it was taking slightly higher rpm to go from 1st to 2nd. But it could be that I am used to daily driver having 8 speed auto. The shifts up or down or reverse were smooth. Having just replaced a pressure line selinod in my daughter’s car, not close to the ‘banging’ on that type of gear changes.
I have asked the restoration shop to deliver the car as is with the auto issues. Once I get it back I will follow up on your directions.

While I am not a mechanic, I am fairly hands on on cars. As such, would rather take my time and look at trouble shooting, instead of reinventing the wheel by yanking out the driveline.

Thanks again