Just finished having a mechanic friend do a timing chain/tensioner job on my car. He's not a Jag/Ford guy but is very talented under the hood of pretty much any vehicle, and he had access to the manual for my car. Sadly, the prior owner only did the uppers, and I had developed the "death rattle." The job is done, and $3k later with new pulleys, water pump, PS pump, and a full set of chains and new tensioners, the car is running great. I am left with one nagging question though, and I'm hoping someone on the forum may know the answer.

The crankshaft seal used in round 1 of the repair was OEM, and it came with a red plastic insert in the center of the seal. After the car was assembled and test driven, it had an oil leak coming from this seal. Got an identical replacement seal from the parts vendor, disassembled and found the plastic cracked, replaced, reassembled, and once again, oil leak at the same spot. Disassembled, found the plastic had been crushed, and for round 3, ordered the seal from another vendor, which came without the plastic insert. At this point, the original seal had also been dug out of the parts pile to find that, likewise, it did not have the plastic insert. After the new seal without the insert was installed, no leak.

My question is...the part number for the plastic insert seal shows as compatible with a 97 XK8, but clearly it was not given the failures we experienced (worth mentioning that the part was properly torqued when installed...twice). The vendor never mentioned or questioned us re. more than one seal option, but I've since noticed that there are two versions of this seal (with/without the plastic insert) available on the Web from different vendors, both of which say that they are compatible with my vehicle. I've looked at photos/videos of the seal installation on the forum and YouTube, and they clearly showed that the ring is to remain in place when reassembling. I had thought that it might be something to assist during installation, then be removed, but that clearly isn't the case in the photos/videos I've looked at.

So, I'd like someone to solve the mystery. There's only one seal, and no mention of plastic or not, in the repair documentation or in anything I've looked at on the Web. So, why are there two versions. Perhaps worth noting, my 1997 was actually a 1996 (early) first production run vehicle. Maybe Jaguar/Ford, changed the part? But still, you would think that there would be some documentation in the service or parts manual calling attention to this...or perhaps not? This seems like a good Jaguar trivia question...?

For reference, I'm including a photo of the original seal, on top, and the two failed replacement seals with the red plastic inserts.


1997 XK8 crankshaft seals

 

I posted a comment to O&DR Modurol, who publishes a TON of fantastic videos on XK8 repairs, and that's where I saw the video on the camshaft seal procedure . In the video, it appears that he leaves the plastic ring in place when completing the installation, and that and other online photos led me to believe it was part of the seal even though it seemed odd. However, he replied that he removed the ring (off camera) and didn't show the seal again (with the ring removed) as the work was completed. In hindsight, it makes good sense that the plastic was just protective, but it's odd that some parts suppliers provide it and others do not. Likewise, hindsight allows one to think about the logic of how the seal wouldn't work properly with the plastic and how the plastic would crack with that much compression being applied. Sadly, this fooled a mechanic who does a lot of engine rebuild/performance work, and me, although this level of work is way out of my mechanic skill league!

Would be nice if there was something posted on this that I'd have come across before doing the job, but perhaps this post will help another Jaguar novice to avoid my rabbit hole.

 

I don’t see how the seal can function properly with the plastic bit in place.

Admittedly I don’t have direct experience in installing this part, but of the many 100’s of crankshaft seals I have replaced over the last 6 decades, on a wide range of engines, none had such an arrangement.

Z

 

That plastic ring is in there just for protection of the seal lip until installation.

 

seems like a solution in search of a problem.


Z