Well, this is kind of a drag. Ever since I bought this car roughly 19 months ago, the manual transmission had a little hint of a "clunk" when you let off the clutch. I always just wrote it off as a very aggressive clutch engagement and thought nothing of it.

Well, now I'm experiencing what seems like synchro bearing failure, and I'm wondering if that "clunk" wasn't just a precursor to what I'm dealing with now. The car has 92000 miles on it.

The transmission will shift into every gear just fine while standing still. If I accelerate very gradually and shift at low rpms, the shifter will drop into place from gear to gear fairly quickly - just about normally - with just a little extra pressure from my shifting hand. As I increase the rpm of the shift points, I need to increase the pressure on the shifter or have a great deal more patience for the shifter to drop into place. That effect starts at about 3000 rpm. Much above 4000 rpm, it wont shift at all. Exuberant acceleration, like on a highway acceleration lane, "just ain't happenin'."

Downshifting has similar difficulties, and often requires rev-matching via the throttle, and is frequently accompanied by some gear grinding. Again, lower rpm shift points work much better.

It's behaving as though the synchro bearings just aren't willing to turn at higher rpms.

Putting it all together, I'm confident that the clutch itself and related hydraulics are doing their jobs properly. I can hold the clutch pedal down and there's no change in the pedal pressure or any gradual engagement as though from leaking fluid. Over the weekend, I checked the fluid level and it was just under the full mark. I bled the line anyway and topped off the fluid. No changes.

I have a subscription to AllData, and they supply the manufacturer's diagnostic procedures and a Symptom Chart. For "Poor Gear Shifting" the chart reads as follows:


Significant effort required when downshifting or synchronizer crashing

Possible Source(s):

• Gear synchronization is inadequate. Action(s) to take:
• Check oil level.
• Check gear linkage.
• INSTALL a new transmission.

Gear jumps out of engagement while driving
Possible Source(s):

• Worn or broken synchronizer components.
• Manufacturing error (incorrect gear wheel toothing or synchronizer ring). Action(s) to take:
• INSTALL a new transmission.

Gearshift problems in different gears (stiff or partially seized)
Possible Source(s):

• Gear linkage. Action(s) to take:
• Check oil level.
• Check gear linkage.
• INSTALL a new transmission.

Brief scratching noise during gear shifting
Possible Source(s):

• Inadequate gear synchronization. Action(s) to take:
• Check oil level.
• Check gear linkage.
• INSTALL a new transmission.

I'll try checking the tranny fluid level or even changing the tranny fluid this weekend. I changed it several months ago in an effort to smooth out the then-barely-noticable shifting issues.

I'll also check the gear linkage.

But it looks like I'm facing a very expensive transmission replacement. <sigh> Does anybody have any other ideas?

 

Sure sounds like you need to bleed the clutch system and/or replace the master cylinder (a known problem). Clutch is not disengaging fully. Mine does this and I need a new clutch master cylinder. It's sticky and not providing full motion.

Try pumping up the clutch pedal, prior to your shift. I'll bet you that the shift goes fine. In any case, shift easy, because you are loading the synchro's harder with a dragging clutch.

Bad syncro's cause grinding.

 

Cujet,

Thanks so much for chiming in. When I first read your message, I was pretty skeptical because I hadn't read about many master cylinder failures on this forum, but after a quick search, I saw the pattern, and it's consistent with what I'm experiencing.

After calling my local Jag dealer for a price on the part ($130-ish), and then calling three aftermarket parts suppliers (Advance, Autozone and NAPA) only to find that they can't get a replacement for this car, I finally called Nalley Jaguar. After factoring in a Jaguar Forums discount, I'm paying $99 for the same Jaguar part, I'm not paying any sales tax, and they're shipping it to my office at their expense.

AllData says it'll take 0.5 to 0.8 hours to replace the master cylinder, and that's certainly a job I can do in my driveway. That's a big difference from the 20 or so hours of labor that I'd have been paying for someone to swap out the tranny with a used part ($1100) or a factory-remanufactured part ($3000) or a brand new part ($5000). And I can live with having to shift patiently for a few more days, if that's all it's going to take.

Anyway, I'm glad you spoke up. That's a big load off my mind going in to the weekend.

 

You are welcome!

At the very least, it's cheap troubleshooting, shotgun style.

As I mentioned, mine does this. I've not changed my clutch master cylinder, as I had planned on selling. However, now that the transfer case is fixed, my car is once again a joy to drive...

Plus, I could not find the master cylinder. It's inside the car. Never looked there.

 

I had some time today, and wanted to rule out some concerns, so I took the car over to the shop that I have access to, and I checked the tranny fluid level and shift linkage. The shift linkage seems fine, and there were no visible signs of oil leaks at or around the transmission. Both the drain plug and fill plug were tight and sealed.

The tranny fluid level was just under the fill hole, but I decided to top it off anyway just to see how much more fluid it might take. It took about a 1/4 of a quart, which probably means nothing. When I changed the fluid about a year ago, I put in the exact 1.8 liters that the factory calls for, so I'm not surprised that there was a little room left before overflowing the fill hole.

Regardless, there was no change in shift quality, so now I wait until the replacement clutch master cylinder comes in and I'll take it from there.

 

If you order a clutch master cylinder, tell the parts department that they'll find this in the section for the clutch pedal, not the section for the clutch itself. If you don't identify the right part, they might inadvertently send you a slave cylinder (with integrated release bearing). For what it's worth, the X-Type clutch master cylinder part number is C2S41449.

Noting it here for the sake of the next guy....

 

But wait - there's more!

Last weekend, I replaced the clutch master cylinder. I followed directions that I got from AllDataDIY.com. They usually get their directions from manufacturer literature. In this case, AllData was wrong about the procedure. It appears that their directions were lifted from those for a right hand drive (RHD) vehicle, and some of the diagrams were merely reversed for the LHD market. Most everything was accurate, except for the very first step that describes disconnecting an engine wiring harness from its mounting bracket on the intake manifold. That harness is on the (driver's) RIGHT HAND side of the engine compartment. There's no need to touch that harness on a LHD vehicle. The only reason anyone would need to loosen that harness mount would be to get more room to access the clutch master cylinder that would be mounted on the right side of the firewall in a RHD vehicle.

On a LHD vehicle, the clutch master cylinder is mounted on the left side of the firewall. It's bolted in from inside the passenger compartment, but you'll need to get access to the hydraulic lines in the engine compartment. To get a clear shot at this, and to get your hands in there, you need to unbolt and partially displace the engine coolant overflow tank. Remove the two small coolant lines from either side of the tank, unbolt the single screw holding the tank to its front bracket, and pull the tank up and foward by a few inches. Then you'll have the clearance to reach the hydraulic lines.

Hopefully, this tip will help someone out when they go to replace their own clutch master cylinder.

BUT WAIT! There's even MORE!

Replacing my clutch master cylinder didn't solve my problem. I should have thought it through more before I jumped on this as a solution, because in hindsight, there were counter-indicators that I should have recognized. I was able to shift into any gear while standing still. This, again, validates that the clutch hydraulics are working fine. It also suggests that the gear shift linkage is fine. Problems start to appear only when shifting while moving, and are considerably worse above 3k rpm. Neither the linkage nor the hydraulics would have any rpm-dependent functionality.

There is a possibility that the release bearing might be sticking - and this is a part that is integrated into the clutch slave cylinder assembly - but this is not a hydraulic failure, per se. I spoke with one independent shop, and their strongest suspicion about my shifting problems points to the slave cylinder/release bearing.

I'm thinking it's more likely a failing dual-mass flywheel that has broken in a manner that prevents the clutch from fully releasing. It's an expensive part - $700 - but it's right there among the slave cylinder and clutch if you're already digging into the drivetrain that far. BTW, all of this is about a 16 hour job, as per AllData. I'm thrilled.

Just thrilled.

If they dig into it this far, and don't find any obvious problems with either the slave cylinder/release bearing assembly or with the dual-mass flywheel, then that means I need a new transmission. $1100 for a used one. I think it's unlikely that all synchros failed at once, with no funky gear noises or other indications about internal transmission problems.

This is going to end up being a $2500 to $3600 job.

 

Update??

 

$3000.

That's 16 hours of labor at $90 per hour (16x$90=$1440) from a local independent shop. Clutch kit (disc & pressure plate) and slave cylinder were $650, sourced through the indy shop from a local Jag dealer. Add in a new dual-mass flywheel that I sourced from Nalley Jaguar for $616, plus the master cylinder that I installed myself, new fluids, plus 7% NJ sales tax on some of this stuff, and we're right around the $3000 mark.

All that on a car that's worth maybe $8000 right now. On the other hand, to not do the work would have meant WAITING to sell the car at a bargain price to the right buyer who wants a discounted project to invest in. Now I have a reliable car again, that I really like driving. At least that's the operating theory.

The clutch disc itself is what failed. Some of the friction material actually tore from the backing plate. Picture a dinner plate with cardboard medalions glued around the perimeter, and then tear one of those medalions up off the plate so that it's still attached, but visibly torn, and you'll have a good idea what this looked like. (I'll try to grab a photograph later and post it.) The end result was that this torn friction material protruded off the disc by a millimeter or so, so the disc never completely disengaged from the flywheel when you'd step on the clutch. I still don't understand why it shifted fine at idle when standing still, but it's fine at any speed and rpm now.

The dual-mass flywheel had visible signs of overheating. The clutch-mating surface was blued - overheated metal - and if you moved the two masses against each other, you could hear that the internal lubrication was depleted or had otherwise failed. The new DMF didn't sound like that, and the springs had much less circumferential play in them. FWIW, the center bearing had no significant play about it, so this probably WAS NOT the initial cause of my problems, but was damaged by the failed clutch disc.

The first slave cylinder that the shop put in was actually defective. Unfortunately for the shop, they had to go back in and do all of that labor again in order to remedy that defective part. The Jag dealer that they sourced the part from replaced the part at their expense, but the labor was out of the shop's pocket. I'm glad I didn't take this job on myself. It's not beyond my technical skills, but it would have been way beyond my patience reserves just from the first time.

Anyway, I'm back on the road. The car shifts smoother than ever. (The new clutch disc is a spring-loaded design. The original disc was unsprung, like some street/strip and racing clutches that I've seen.) And I could swear that the car accelerates faster. Probably from my wallet being so much lighter!

 

Thanks so much for the informative update. I'm glad to hear all the gory details. As my car is acting up a bit. I know what I'm dealing with.

 

A few weeks ago, I said that I'd post some pics of the clutch parts that came out of my car. Well, after tripping over the box of parts in my garage today, I finally remembered to grab my camera....

The first is the assortment of (clockwise, from the top) the integrated slave-cylinder/release-bearing, the dual-mass flywheel, the clutch disc, and the pressure plate:



Here's a close-up of the dual-mass flywheel:


There's really nothing about the appearance of the flywheel that I would call particularly suspect. But as I said earlier, we were already there, and nobody trusted the thing, so we replaced it as a precaution.

But the picture of the clutch disc itself really tells the story here:



The friction material is NOT SUPPOSED TO SEPARATE from the disc like that. Normally, a clutch just wears out, and the friction material gets too thin to make good contact with the flywheel. Not this one! It broke, and considering the design of this drivetrain - with a dual-mass flywheel that's designed to absorb the impact of any abuse at the clutch pedal, and with a transfer case that's so commonly reputed to be a weak point that you would think it would fail first - it doesn't follow that this clutch failure could have happened from anything but a manufacturing defect or design flaw.

And again, for what it's worth, the new clutch discs are spring-loaded for smoother take up, unlike this factory-original 2004 clutch disc. The redesign (or re-specification in the parts ordering) of the disc may be indicative of some recognition by the factory of the existence of a problem.

If I'm right about this being a defect or design flaw and not the result of some driving abuse on my part - unlikely, given my driving style - or on the part of a previous owner - unknown likelihood - then other manual transmission X-Types are going to experience the same failures.

 

Rothe,

On the clutch you picture, what's the mileage and how aggressively do you drive?

 

92000 miles. I don't do clutch drops, but that engine sees high rpms regularly. In summary, "enthusiastic" driving of a manual transmission vehicle.

 

My Jaguar (2004 X Type) appears to be exhibiting the same problem. I can run through each gear with ease at low speed/RPM but one I get above 2000 RPM, everything changes. if I get through to 4th gear before 2000 RPM, and not stalling the vehicle, I'm fine. Off to 5th I go. OK on highway until I have to reduce speed and need to shift down. I can't down shift at all unless at very low RPM. After reading your post, I'm going to have the clutch replaced first. Hoping that this takes care of it. My local mechanic seems to be guessing and I can't afford each time he tries to figure it out. You may have saved me a few thousand with your post.