63 Mark 10 Intermediate Hold solenoid

The intermediate hold solenoid on the rear of the transmission leaks a considerable amount of transmission oil from the outer rubber seal. It does work and it comes rather handy since my neighborhood has a few hills that require me to use the solenoid frequently. I have not removed it yet to inspect it yet - are these rebuildable? I am suspecting the rubber seal is toast.

Adding a couple of pictures for reference

I have dug out my Service Manual for the Jaguar automatic transmission Publication E 113/5 and it shows some useful cut away drawings of the solenoid and how it fits to the housing. It appears there is a item called a bellows that seals the solenoid from oil in the transmission. This item looks like a very small version of a steering rack boot. I suspect yours has perished. The oil shown on your photograph is on the boot at the outer end of the solenoid and it is not intended to contain oil, only as a dust cover for the end of the solenoid. The oil leakage is more internal. Unfortunately, I do not have scanning capability but email me off line and I can arrange to photo copy and send you relevant pages for your use.

John Quilter
Eugene Oregon USA

I took the solenoid out and removed the dust boot (actually, destroyed it). The electrical side of the solenoid was choke full of transmission fluid. That means that the solenoid is internally leaking… are there replacements around?

It is not the solenoid that is leaking but the leakage is occurring further inside the casting the solenoid mounts to. That is where the bellows that controls leakage is located. Replacing the solenoid will not cure your problem. Going my my 3.8S factory parts manual what you need is Guide tube and bellows assembly for intermediate speed hold, Jaguar part number C17678.

The bellows is definitely trashed. As part of a re-seal kit I got on ebay some time back, the bellows came with it but not the guide tube. I guess I could attempt to glue the new bellows on the guide tube and hope for the best? I doubt that you can get a new guide tube with bellows attached…

On the other hand, SNGBarratt has this replacement solenoid. It looks like the new design, prevents leakage into the solenoid even if the bellows fails…


The brand new bellows tore itself apart when I tried to install the assembly into the cavity… it may have been NOS - looked new but was rotted??? back to square 1.

Try Graham Whitehouse in the UK; highly regarded for repairs / rebuilds of these transmissions so must have the parts.

I can affirm Tigger’s recommendation. I had Graham rebuild the DG250 transmission from our 1963 MK2 and it now performs flawlessly. As a bonus, it’s absolutely leak free now! Graham will have the necessary part/s to seal this up.

Our Borg Warner transmission exhibited the exact same leak that you are experiencing prior to the rebuild.


Graham did the DG in our car twice - 14 years elapsed / 50,000 miles between each. Would have been longer but I was let down by another ‘expert’ who maladjusted it during a service leading to excessive / premature wear.

Well, I cannot quite ship the tranny to the UK for repairs… any way, I found two sources for a replacement bellows - one from SNGBarratt for $48 and another one on ebay for $70(!!) (https://www.ebay.com/itm/Jaguar-DG250-DG150-DG200-M-Auto-Transmission-Speed-Hold-Bellows/153045574416?var=null)

Are these prices justified??

$48 is quite acceptable imo, especially if it fixes the issue…unless you want to go to some CV or steering specialists and see if they have something generic & much cheaper, but might be a couple of hrs mucking around

(I put a seal in my steering box, and it leaks worse than before)

does the DG have a “shifter select seal” ? they leak in the later BW trans, mongrel thing to get at

I did get the replacement solenoid from SNGBarratt which, according to their description, would fit the transmission on the Mark 10. The original plunger has a cavity in the front which receives a shaft from the innards of the transmission. So, the total effective length on the plunger - original vs. new design matches. However, the boot, which is meant to prevent ingress of transmission fluid into the solenoid, does not fit at all. Has any of you fitted the new style solenoid?

Found this thread while looking for a solution of exactly the same problem I am experiencing with my MK2 3.8 Auto. Has anybody ever tried to do away with the solenoid completely and blank off the opening? Studebaker’s gearboxes are supposed not to have the ISH. Hence, these gearboxes should have something like a blanking plate. Just can’t find the part, and I do not know what will happen if I just make up a suitable lid with a gasket and close the opening where the solenoid sits.

I also would like to know about this as I am not yet ready to do the complete 700R4 swap. I can’t keep the transmission full as it leaks so badly. A blanking plate was an idea I did not pursue.


I was able to procure a couple of bellows @ $28 a piece - one for the immediate repair and one as a spare. I called Northwest Transmissions and talked to Chris - they had the bellow and it was identical to the original one. I was able to use the new solenoid with the old shaft fitted with a brand new bellows. The pressure pump needed two gaskets which I had from a kit that I purchased previously - I drove the car a few miles and I am proudly able to say that the nasty leak is fixed!!! This leak was a real bad one - it would continuously drip (into a drip pan) at the rate of 16oz month. Woo Hoo!

Removing the solenoid and blanking the opening up was not an option for me. I live in a hilly neighborhood and being able to shift to 2nd gear at a flick of a switch is a necessity.

Always good to hear of an owner’s success story on a technical issue. We all learn from other’s experiences.

John F. Quilter
Eugene, Oregon USA

Unfortunately, the leak is back, from the same position on the new solenoid. Definitely not as bad as before but still evident when you leave the car sit for a few days. I either did not install the bellows in relation to the gasket correctly or this contraption always leaked from the factory. You can see the transmission fluid slowly oozing out of the red electrical wire connection

can you make any more comments about the part and its installation? did you have to remove the new solenoid’s bellows to get it in the opening? did you have both bellows installed (the stock one and the new one on the solenoid shaft), and still get a leak? is the operation/function of the part good? mine was completely destroyed somewhere during PO possession. terminal end was bashed out and goop and washers use to seal that space, then solenoid was disconnected.