Moss Motors, Ltd

I have an '85 XJ6 Vandenplas SIII with a transmission that doesn't shift until warmed up.  In the morning it sticks in 1st gear until I have driven it a copule of miles then it starts reluctantly shifting but will stick in whatever gear it was in if I stop until it has warmed up completely.  I would like to hear if anyone else has had this problem and, if so, what cured it.  BTW, the car has been carefully maintained, has plenty of tranny fluid (possibly even a lttle too much), and the car has 75K miles.  It has had no tranny problems in the past.

Thanks, Joseph

Greetings man!

 

Before offering my humble opinion, of which I have many, I would first ask has the car sat idle for any length of time in recent months?

You say it has been maintained, does this include complete transmission fluid changes filter included?

Even if so well maintained the transmission is now over 20 years old and even with low miles age is a factor. 

Things can gum up if not thoroughly kept up. BTW, too much fluid is not good either.

 

I think I have had every common problem with Jags there is. Changed the trannie on my XJ-6 once and pray I NEVER have to on the V-12's. 

Co-incidentaly I also have an '85 VDP (XJ-12) also with about 75000 miles on the clock.

It has a sticky tranny somewhat like what you describe.

Your car isn't charcoal grey by chance is it? 

It was a one owner car until I bought it and documented maintenance going back to the day of delivery.

 

I also have a 1987 VDP V-12 with seven previous owners, that has 175000 on it and it works perfectly 

 And a '87 Soveriegn XJ-6 which has a very sloppy 300,000 miles on it and it runs so well !!

Am I saying Jag's thrive on neglect?

No but, of all my cars the '85 has had the best care, best 'provenance' and gives me the most trouble.

As well as the most FUN! It is FAST FAST FAAST!

 Hate to ramble on like this, but it may not be as simple as it looks, or as complicated either.

 

Hard to diagnose a trans problem on a forum, and also easy to get driven crazy by wild guess's 

 Good used later version S-III six cyl trannies are not easy to come by and not cheap to rebuild. 

 (Bad ones are plentiful tho)  Do get it looked at by an expert before it lets you down.

                                 Cheers,  

Joseph:

I bounced the symptoms you described off a friend of mine who specializes in auto trannies.

His initial tentative diagnosis was that either the governor pressure is leaking past the front sealing rings or that the line pressure is too high due to a worn out valve body. Either is not good and would require a rebuild to fix. The Ser III is a lovely car, but it does not have the best reputation for transmission longevity.

Sorry for the bad news. Since I am not a transmission expert and am passing on second hand information from someone that has not seen your car, I would recomend getting the opinion of a qualified local transmission expert before doing any work.

all the best

 

 

 

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Kelvin Dodd
Global Sourcing Engineer
Moss Motors, Ltd.
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Disclaimer: Working on automobiles is inherently dangerous. Moss Motors, Ltd. is not liable for injury or damage due to incorrect installation or use of their products. All products are sold with the understanding that the safe and proper installation and use of the products is the customer’s responsibility. Follow factory workshop manual procedures and instructions, but use current shop safety standards and common sense. Some tasks will require professional advice or services which Moss Motors cannot provide.

Thanks for getting back to me...  I just got the diagnosis from the tranny shop and they believe a rebuild is in order.  They did a "power flush" which improved things slightly...but the problem is still there.  The car has sat a lot over the last 3 years...lack of use is the worst abuse...   It is a beautiful car (maroon by the way, bought in SoCal 10 years ago.

 

Kelvin,

Thanks for your reply as well.  See my post to the other gentlemen...  Your diagnosis appears to be accurate.  I assume there is no transimission fluid "additive" that would help??  After the power flush things did improve slightly...  Does Moss sell rebuilt trannies for the XJ6 - it is the Borg Warner?

Regards, Joseph 

 

 

Joseph:

Sorry, but Moss doesn't do rebuilt transmissions for the XJ. Since your car is low miles it would probably be worthwhile getting your transmission rebuilt, rather than going with an exchange unit. Back when I sold Jag parts, I had a number of wholesale customers bemoaning the fact they could not get good rebuilds as the cores were totally worn out.

good luck.

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Kelvin Dodd
Global Sourcing Engineer
Moss Motors, Ltd.
Helpful Links:
Code of Conduct
FAQs

Disclaimer: Working on automobiles is inherently dangerous. Moss Motors, Ltd. is not liable for injury or damage due to incorrect installation or use of their products. All products are sold with the understanding that the safe and proper installation and use of the products is the customer’s responsibility. Follow factory workshop manual procedures and instructions, but use current shop safety standards and common sense. Some tasks will require professional advice or services which Moss Motors cannot provide.

a friend with an '85 XJ-6 had serious problems with his transmission too, I referred him to 3 shops in Orlando, Florida for estimates to rebuild or replace his with a used one. One of the shops quoted him a rebuild for $1,200. (all included) and 12 months warranty. I thought that was a good price. There is a rebuilding Kit available, part number or contents of kit are unknown to me. Your car has the BW66. There is no BW67, but there is/was a BW65 used in earlier cars. Another shop gave him a price for a used one for $350.00 but no install.

Depending on your location, prices will vary! I am told that these Borg Warner transmissions are not 20 years old, they are 45 years old,  they were first used in Studebakers and who knows what else, so there are parts available all over the country, and the people who can restore them fine. So don't despair! I must be lucky, because I have had no such trouble with my 1984 XJ-6, (which I have owned for the last 16 years!) and the transmission shifts very smooth, and I drive it hard such as using 2nd gear for braking the car when needed, for example, stopping from 90mph. Yes, these XJ are fast alright, they show their ability after 80mph, when they morph into a "stingray", cutting through the air like a  knife So drive carefully.

Jose
 

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1984 Jaguar XJ-6
1965 Jaguar 3.8 'S'

Kelvin,

It is 9 months later and I finally got my car into a shop to get the transmission rebuilt.  The shop that has it now believes that it is a Jaguar M20 transmission that was only built by Jaguar for 2 years.  It is a good transmission shop but they do not specialize in British cars/trannys and they are having a difficult time finding parts.  Are you familiar with this transmission?  And do you carry parts for it (I do not see anything for a M20 or Model 20)?

Thanks, Joseph