Stuck Transmission Filter Bolt


(OmberJag) #1

Hello,

When I first attempted to change the transmission fluid and filter after buying my 1990 4L model XJ40, I discovered that the bolts holding the filter in place were done up very tight and their heads were stripped. Unfortunately the worst case was the round-headed bolt in the contre recess of the filter, which looked completely rounded out, and my screwdriver was slipping with only the slightest turn. Unprepared to deal with the problem, I left the old filter in place and just replaced the fluid.

Now it’s time to change the fluid again, and today I attempted to use a head-gripping screw extractor on the stuck bolt. Unfortunately with such a big round hole in the bolt head already, this only helped to make it bigger and rounder. I’m too nervous to use one of the drill-in types of screw extactors because I worry the the bolt won’t be wide enough and might split in place (plus the last time I tried them on this car I went through a whole pack, breaking and then drilling them out one-by-one (instead I drilled through the bolt itself in the end)).

So, my questions:

  • Are there any other options for removing the bolt? My next guess is to use a cutting disk on a Dremmel to cut a slot into the bolt, but if I slip and put a hole in the filter, then still can’t get the bolt off, I’ll be stuck. This thread (which I didn’t find before, the search on this new forum site must be better) suggests that as an option though: [xj40] Torx heads on transmission filter bolts stripped

  • What are the specifications of the bolt? I asked Jaguar this, and whether they sell replacements, last time, but they couldn’t help. Of course I can measure it once it’s out, but then I’ll have to stop mid-job and drive into town to get a new one (and hope they have one suitable).

  • How irresponsible would it be to leave the same filter on again, and perhaps for ever after. This thread gives me confidence that it might be an option: [xj40] Transmission Fluid/ Filter Change? . If it makes any difference, the fluid that came out of it today looked like new.

  • While we’re on the topic - the black thing in the round dimple at the bottom of the pan. It looks like the magnet, but a gooey black stuff comes off when it is touched, I’m afraid to try cleaning it in case it’s not a magnet and I end up cleaning it all away. Advice welcome.

Thank you for reading.

The bolt hole where my problem is, circled in red:
Jag%20GB%20Sump%2C%20bolt%20marked


(Rodney ) #2

There will be a magnet in the sump and it will be more than likely covered in black goo, just wipe it clean. As long as there are no iron filings attached it should be okay.
Will removing the filter any which way you can give you more access to the bolt head?


(OmberJag) #3

Thanks, I’ll clean the magnet before refilling the oil. I guess I could have just held a screw driver over it to check… Oh well.

If you mean cutting around the bolt, that would help, but it would be tricky. I’d be worried about cutting into the gearbox underneath.


(Brett) #4

I understand your dilemma as you don’t want to put yourself in a situation where you can’t just put it back together if your attempt doesn’t work. I think we’ve all been there at one time or another.

Can you try heat, or my preferred method, welding a nut onto what’s left of the bolt?


(OmberJag) #5

Yeah, to be honest I’m sort of hoping for confirmation of that thread I found where it was suggested that the filter doesn’t need to be changed. But at the same time I’m a little dubious.

I wouldn’t want to take a welder to it because I have an electronics background and welding around all those sensor wires in the gearbox is likely to cause nasty voltage spikes generated by the magnetic field to travel back to the control electronics and sizzle them. Plus I’m not sure how well I could do it in the space I’ve got to play with under the car.

Heat sounds interesting, though I’m not sure how you mean to use it. I’ve got a blow torch, but wouldn’t heating a bolt just cause it to expand and sieze even more?.. Well I’ve looked it up on the web and it sounds promising (bolt cools in a slightly different shape to how it was before). I’ll check how flammable the transmission fluid it first because it’s coating everything.


(Robin O'Connor) #6

I would be very wary of using a flame on the bolt If the fluid looks in good condition coming out I would be inclined to just leave the filter in place, clean the magnet and bolt things back up.
With regard to the Torx bolt it will be a standard thread so you would not have to source a torx head if you do manage to remove it.


(Brett) #7

To be honest, I’m not sure at what temp transmission fluid ignites, so its certainly something to be wary of. Sounds like it may not be an option anyway due to lack of room to work.

Possibly you could try the opposite and use dry ice or something to freeze the bolt loose.


(Casso) #8

Hi, I’ve had success removing damaged torx head bolts in the past using a socket that is slightly smaller than the head of the bolt. With the socket fastened on to an extension bar use a hammer on the end of the extension to force the socket over the bolt head. If you use a multi point socket rather than a hexagon type the points press grooves into the bolt head and give it grip, also the knocking helps shock the bolt loose.
Good Luck.


(Robin O'Connor) #9

There is a can of freeze off that might help as well, not sure who produce it but its available in NZ so surely it must be on the shelf elsewhere :slight_smile:


(OmberJag) #10

Thanks for the suggestions.

Tomorrow I’ll have a quick go at the socket and hammer method, though I think the rounded head will likely work against me, then try cutting a slit in the bolt carefully. Failing those, I’ll leave the filter there and at least rest in the knowledge that I tried.

I’m slightly tempted to use a CO2 fire extinguisher to freeze the bolt, but they’re not cheap so it would be a bit of a waste. :slight_smile:


(Robin O'Connor) #11

A Dremel is useful in this area. I have just modified the calipers for my ‘65 ‘S’ the pistons are pitted and I am using new ones that are the correct size but do not have the retraction mechanism so I removed the pin in the centre with a (many)1mm cut off wheel


(Casso) #12

Hi, Is there enough room around the head of the bolt to get the jaws of a reversible drill chuck to tighten on to it, ?


(OmberJag) #13

I think that filter’s staying there.

A 7/16" (I think, I can’t be bothered going back to the shed to check) socket can be hammered on to the bolt head, but there’s not enough for it to grip on to so it twists off way too easily.

I used the flexible extension arm on my knock-off Dremel, which let me get nice and close, then ground away with the cutting disc on a low speed setting so that it wouldn’t cut through the filter if I accidentally caught it. The result was a great slit which perfectly fit the flat-head bit for my impact driver.

So I wacked the impact driver with as much force and the largest hammer that I could use in the space under the car, then put the bit in the cordless drill and pressed with enough force to push up the whole gearbox, but the damn thing just won’t turn and it just ends up slipping out. The slit isn’t stripped out and I tried various big screwdrivers (where the problem is that I just can’t turn them), but that bolt isn’t moving.

Last resort would be to use a bottle jack to somehow push the bit in from the floor while I turn it via a bar of some sort. I actually tried that with the drain plug on the diff. (including making up, and breaking, tools to do it) but failed (instead, I made up a device to suck the diff. oil out of the fill hole using a suction pump, pneumatic tubing, and an old fire extinguisher). For this, I’m not going to go that far - too much trouble and too much risk of damage.

By the way, off the top of my head this is the seventh seriously stuck bolt that I’ve found in this car in the few years that I’ve had it, and it will be the fourth that I’ve given up trying to undo (or otherwise remove). I think at some point it must have been reassembled by King Kong :slight_smile: .

Anyway, if I get enough strength back in my arms today, I’ll clean off the bits of metal around the bolt, put the sump pan back on, and fill her up with fresh fluid. At least the old filter survived with just one scratch.

Oh, and if anyone has wondered if the gearbox will stop dripping fluid all over them if they leave it long enough after draining the sump, it hasn’t yet.

@Casso No, and I think the bolt head is too rounded for that anyway.

Thanks to everyone for the advice.


(Grooveman) #14

If you haven’t buttoned it up yet you could try one more thing …

Take the biggest screwdriver that will fit into the slot and put a pair of vice grips on the shaft. Now slide a piece of pipe over the adjusting arm of the vice grips. This should give you plenty of torque on the bolt. Ideally you can get directly under the screwdriver to apply upward pressure while an assistant turns the pipe. This way you can put slow steady pressure on the bolt head while keeping the screwdriver from popping out.


(Mike Stone) #15

In lieu of vice grips, if your screwdriver has a square shaft, use an adjustable (Crescent) wrench. Combine that with your idea of using a bottle jack to supply upward pressure on the screwdriver. Good luck.


(Alan Grossman) #16

Might also try going in the direction of tight a time or two.

Cheers, Alan


(Casso) #17

Hi, A picture saves a thousand words, now I’ve seen it close up I can see how the socket or drill chuck ideas wouldn’t work. I was thinking the bolt head was similar to a standard socket headed cap screw with straight sides rather than a dome headed one like that.
The bottle jack idea using a screwdriver you can attach a wrench to, or mole grips and lever might work but
I think if I was in your position now, I too would admit defeat and leave that filter in place. I’d be worried that maybe that bolt’s been cross threaded and forced home, and if it did come out after being over tightened by so much, it would be likely to bring the alumimium thread out with it at the same time.
Good luck whatever you decide.


(OmberJag) #18

Thanks for the tips but I’ve already put it back together now. The drill that I used is quite controllable at slow speed so I think the next thing would be trying to push up with more force. Remembering how dicy (and ultimately unsuccessful) my attempt at using a bottle jack to undo the diff. drain plug that way ended up getting, I’m not going to risk ending up with a stuck damaged filter, or worse.

The wire mesh that I can see through the hole in the filter looks clean, so I’ll take that as convenient proof that it doesn’t need to be changed.


(Matthew Kennedy) #19

There is another way but you may need a new bolt afterward. Use a centre punch toward the outside, tap lightly upward to start a dimple and when big enough angle the centre punch toward the direction you want it to spin and keep hitting it. You can do it in a few different spots. This way you are not putting any upward force on the threads. You can even use the outermost part of the screwdriver slot as a start point.


(Grooveman) #20

Vice grips vs crescent wrench on the screwdriver shaft …

I believe the key to this is getting maximum slow torque on the screwdriver blade. The adjustable arm of the vice grips is small enough to slide a pipe over it which can greatly increases the moment arm. If you use a crescent wrench you could slide another screwdriver through the hole in the handle for increased torque but I’ve got a scar to prove that this method can be dangerous.