Transmission Fluid Question
 

I blew out my 1967 Jaguar 420 engine (the car has a manual transmission) and then had a 4.2L XJ6 engine put in. My transmission is starting to slip and when I put the car in overdrive it jerks. Is there a transmission dipstick somewhere on the XJ6 engine. What type of transmission fluid should I use? Thanks! Jordan

Hi Jordan, Welcome to the forum. It depends on the age of the transmission and what model it is.
I have a 1973 XJ6 with BW12 transmission. It has a dipstick located just behind the engine oil dipstick.
Originally mine took Type A fluid,which is no longer available but Type F is the replacement. I think after 1977 they used something different again(maybe Dextron II)

Add a photo of your engine/tranmission if you can it might help identify your trans.
I'm sure members with much more experience will be along to add their help shortly.

Visit the new member area and post an introduction thread(link below)

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

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Thanks. The "dipstick" was integrated into the transmission fluid cap...it looks low. What type of engine? What type of fluid would you use? I have a bunch of British cars. I'll start posting some pics in the Garage section. Jordan

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Hi Jordan, I think that is the cap and dipstick off the power steering pump. Is it at the right front of the engine?

The "dipstick" is on the front left if you are standing in front of the car and facing back. The cap says Automatic Transmission Fluid. Thinking this out...it was the engine that was switched, not the manual transmission. I searched on-line and could not find the type of transmission used in a Belgian 1967 4 speed manual with overdrive Jaguar 420. Anyone know the type of transmission & appropriate fluid? By the way I could only find a long oil dipstick on the back right of the engine (facing back to the car again). Thanks! Jordan

o1xjr is correct, what is shown in the picture is the Power Steering Fluid Dipstick, NOT the transmission fluid dipstick.

what you are reading on the cap is the type of fluid you can use in the Power Steering Pump, since automatic transmission fluid can be used in a power steering pump/system.

moreover: Manual transmissions do not use "FLUID", they use a specific grade of ENGINE OIL. (maybe 10 or 20 weight oil).

The reason you can't find a transmission dipstick is because you have a Manual Transmission.

if your transmission is slipping, chances are your CLUTCH is the problem, not the transmission oil.

you need to take the car to a Jaguar mechanic who can properly diagnose the problem you are having.

Agreed.

The manual transmissions use a "graded oil" as said, and usually a SAE80 or 90 in that era of transmission.

The oil spec charts I have access to state "SAE80 Smooth Shift".

Manual transmissions CANNOT slip, so any slippage you are experiencing is purely related to the clutch.

Clutch replacement is the only real way of fixing the slipping.

Grant is correct, it is 80 or 90 grade oil.

Thanks guys. I'll have my mechanic check out the clutch.

So why would it be less smooth & jerky when I put it in overdrive?

And while we're at it...what type of power steering fluid should be used? It was low. Thanks for all your help.

Firstly, clutch slippage is purely a female event. It cannot decide to "drive" or "not drive" the transmission.

The jerking is possibly oil contamination on the clutch facings (which, like brake pads, must be oil free). The only fix here is replaement. Obviously OLD AGE plays a huge part also.

Power steer fluid is simply ATF (Automatic Transmission Fluid), and should be drained and refilled with fresh annually.

Jordan, sorry about the confusion. I assumed you had replaced the engine and transmission since your original question was about transmission fluid.

No sweat o1xjr. Also thanks Grant. That clutch stuff must be my feminine side. Here's a pic of my male hobby:

Nice, less issues than a Jag, HAHA.

go to any autoparts store like Autozone, Advance Auto Parts, O'Reillys, Rogers, NAPA, etc., and buy a pint or two of STP Power Steering Fluid, it comes with or without Stop Leak additives. There are many brands of Power Steering fluids, it really doesn't matter what brand. Normally it is Red in color, but PRESTONE makes a clear-color fluid too which I personally do not like because it can be confused with Brake Fluid, which is always clear.

Note that the power steering pump in your picture is a GM (General Motors) 'Saginaw' pump used in Jaguars starting with the model 420 of 1967 all the way to the Series 3 XJ V12 model made until 1992.