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Hello! I just bought this wonderfully clean 1994 XJ12. The only issue the car has is that it still has the original SLS setup. The system still basically works but the ride is very bumpy and my trusted Jaguar independent mechanic told me the shocks are worn and its time to decide to switch it to traditional or try to source some of the SLS ones. I am going to convert and would like to do the job myself. I have bought the full kit with the longer springs and such from Jagbits. I have the SLS overview Jag put out in 92 and technical bulletin 64-14 that explains the process from 1993 but it doesn't mention V12 cars. from my looking around on the forum it seems there may be some specific issues with the V12 that I should be aware of vs the 6, but I haven't seen the issue explained. I would sincerely appreciate if any of you know how the job differs for a 94 V12 vs the 6 cyl.? Thanks!
I don't have experience with the kit that you got. Did it mention any differences as far as kit number for 6 vs. 12? If the listing for the kit didn't call out a different part number I would say you should be good. One difference would be the presence of the limited slip differential which would not affect your swap. There was also a change in the control arms from stamped steel to cast on the later 94s. I don't think that would affect your swap either since that only involves the lower shock bolt. I'll try to remember to have a look at mine after work. Keep us posted.
Thank you for the help! The kit is supposedly correct for both the 6 and the 12. The post that led to the question referenced a different solution needed for plugging the hydraulic line with the 12 but of course I didn't bookmark it and now I can't find it. It was on a different Jag forum and google is failing me. I will keep looking and will update the post if I find it. It just made me wonder if there was anything else out there to be aware of...
The 12 cylinder 94MY cars may have beefier FRONT suspension, but the rear should be very similar if not exactly like the 6 cylinder 94MY cars.
OTOH, the 94MY rear suspension is quite different to the earlier cars and is actually an X300 system.
The primary difference is that in addition to the cast wishbones and shock absorber lower mount size that Jerry mentioned, the spring is longer and sits on the wishbone, where in all other production year suspensions the spring sits on a collar attached the lower body of the shock absorber.
Shocks for 94MY cars don't have a retaining ring on the lower shock body so if your kit has these rings you need to return the kit as it will not fit your car.
The best approach would be to fit springs designed for a later car, such as the X300 and along with all the the various bushings buy new upper metal plate mounts also for an X300. When I renewed my 94MY rear suspension I used the existing upper mounts (car was not fitted with self leveling when I purchased it) and although they are performing OK, if I were to do the job again I would purchase X300 upper mounting plates as the X300 upper plate is slightly redesigned to eliminate a sharp projection that is present in the XJ40 type.
The job is not difficult and if you check out this thread it may help you avoid some pitfalls along the way!
Thanks for the clarification Larry. I have to assume that if the kit doesn't specify, then it is probably for the "majority" of cars out there. As far as the pump section goes, that pump is specific to the 93-95? V-12 sedans. It is a "double" pump with 2 separate sections in one housing- similar to a heart. We have another member attempting a replacement of it and in a similar situation, maybe he will chime in...
In 2011 I had the SLS replaced on my Daimler Double Six 1993 by a very good mechanic. I used a conversion kit and may well have purchased it from JagBits, but I can't remember as I bought so many parts from so many places when I first got the car in 2010/11. I have been exceedingly happy with how the "kit" has performed. CHS: if your car sat for a long time without driving before you purchased it, you might want to see if the front bushings and suspension need replacing.
I recently replaced the bushings on my rear shocks and suspension and found out that the conversion kit basically "upgraded" my suspension to the later produced X300. The shocks are Sachs 170-122. Originally, the SLS system was "optional"; some cars had it, other didn't. I believe, though I don't know for certain, that the non-self levelling shocks that were originally put on the XJ40s are different to the shocks used in most conversion kits today.
When replacing rear shocks, I would highly advise you to replace parts #15 and #5 in the below diagram. I replaced them three weeks ago. I opted for a polyurethane version of part #5 (Superflex) and have been very happy with how the car has handled and felt while driving. I couldn't find #15 in polyurethane so opted for the original material.
Now, the pump! As Jerry alluded to, I had to replace my tandem PS/SLS pump recently. Thanks again Jerry! It was quite a job that was done by a far more experienced mechanic then me. I love the V12 and it is such a luxury to drive. But, it can be frustrating to work on as any major "operation" requires so much prep-removal to actually get to the part in question. The tandem pump replacement is one such operation. My tandem pump was leaking around all of the seals and hoses and "o" rings.
Then, the whole question came up; since the SLS is no longer operating, can I just remove the SLS hoses and reservoir and plug that part of the tandem pump? My mechanic thought about this but decided that it was best to keep fluid in the reservoir and system to keep the SLS part of the pump from overheating and seizing up. I still don't know if this is true. I drove on my "old" pump for over a month without fluid in the SLS while I waited for my replacement pump and the pump didn't seize up. The power steering component started to leak more vigorously but it was leaking even before all the SLS fluid drained out. BUT, as the SLS is not leaking on the replacement pump, I will keep the reservoir full.
Again, congratulations and enjoy driving your car. This model is such a pleasure to drive.
Charles
See those semi-circular things and those metal pans in the kit illustration?
That system won't fit a 94MY XJ6 ...by the sound of it your VIN is prior to 696459 so more than likely you have a 93MY car registered in 94.
If you have a glove box in the dash you have a 93 so the kit will fit. You could always look underneath the rear and see if the springs sit on the shocks or on the control arm. That would tell you what you have too.
I do have a glove box and only the driver side airbag so it appears I have a 93 registered as a 94. All of the above information in this thread is great and I very much appreciate it!
Now, the pump! As Jerry alluded to, I had to replace my tandem PS/SLS pump recently. Thanks again Jerry! It was quite a job that was done by a far more experienced mechanic then me. I love the V12 and it is such a luxury to drive. But, it can be frustrating to work on as any major "operation" requires so much prep-removal to actually get to the part in question. The tandem pump replacement is one such operation. My tandem pump was leaking around all of the seals and hoses and "o" rings.
Then, the whole question came up; since the SLS is no longer operating, can I just remove the SLS hoses and reservoir and plug that part of the tandem pump? My mechanic thought about this but decided that it was best to keep fluid in the reservoir and system to keep the SLS part of the pump from overheating and seizing up. I still don't know if this is true. I drove on my "old" pump for over a month without fluid in the SLS while I waited for my replacement pump and the pump didn't seize up. The power steering component started to leak more vigorously but it was leaking even before all the SLS fluid drained out. BUT, as the SLS is not leaking on the replacement pump, I will keep the reservoir full.
Charles
Hi,
I am facing the same question. On my XJ12 the SLS was replaced long time ago, but the tandem pump, reservoir and stuff were all left in place. Now it looks like the tandem pump is starting to leak, I have red and green drips on my alternator housing. The steering fluid might also come from the reservoir to pump hose which is not available any more. My idea was to at least empty the SLS reservoir, if not throw out all SLS parts. But what will happen to the tandem pump? Even the official service bulletin mentions nothing about the pump.
I thought about retrofitting a single pump, but that is not available any more, for the tandem pump replacement parts are available.
Also, if I remember correctly, the servo pump casesfrom older BMW 5 series are identical. The pulley needs to be changed over and the pressure regulator valve, too.
Thanks, I haven't found that yet. It's even less expensive than a tandem pump from SNG. But will they accept a tandem pump as exchange? I gotta find out.
Actually I am not too keen on removing that pump, I think it's gonna be a mess and a lot of other parts probably have to come out, too. And I already spent a lot of money this year for the suspension and new tyres. But I don't want to wait until it drowns my alternator (which just came new last year) and leaves puddles everywhere I park it.
01-20-2021, 07:34 AM
V12 Specific SLS Change Issues?
. My idea was to at least empty the SLS reservoir, if not throw out all SLS parts. But what will happen to the tandem pump? Even the official service bulletin mentions nothing about the pump.
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