Jaguar (Salisbury) problems.

[greenwater]

O.K. I've sold my Hawk slabside and bought an old TVR...can I still panhandle advices?? BTW the selling of the slab had nothing else than economical reasons as it is a superb car.

So here I am with that little english two seaters that had a v-8 transplant and am in the phase of bugging it out now.

The differential (4HA) is a nightmare as when the car is engaging turns both wheels at the rear tend to actually brake...I mean brake not making small cling-clung noise! Altough I haven't tried it yet on the road (snow around here) it seems it could just be a pain and dangerous even to drive.It is a 3.55 with a posi mechanism from what I can see (I've opened the backcover yesterday and that what it looks to be).

There are no appearant mechanical reasons ,out of the diff, to do this: no U-joints rubbing,no handbrake dragging.

I have just put in the oil formula as follow: 2 cans of 114 ml. GM additive with 75-90 Castrol Syntech for a total of 1.7 litres. Of course the miracle did not happen and it still does it.

The fellow who sold it to me say he installed new clutch plates and till they wear-off that is how it will work...making sense? My Hawk had a similar diff.,maybe a more recent one, and was just as smooth as it can be.

Is it possible ,tecnically speaking, to have such a differential but locking it definitly?? the ex-owner was a dragging fan!

I would appreciate all suggestions,
thank you, Ronald.

[RallySnake]

Ronald,

After I had my Jag-you-are rear end rebuilt by the somewhat famous Hoopers shop, I was warned that it would be noisey for awhile. On tight turns, it made some pretty scary clicks and clunks. After three years, it has gotten much quieter. It seems to work well and I guess it takes a while for the clutch packs to break in.

My gears do start to howl once in a while even now, especially at high speeds. Since the unit is bolted directly to the frame right behind the seats the noise is awful. The guy at Hoopers recommended that I separate it from the frame with rubber bushings or something. I don't think this is possible without affecting the handling of the car. So, I'll live with it.

Paul

[John 550]

If all the teeth on the spiders checked out good ,
put in another tube of GM additive .This is just what was sugested to me ,
and it what was needed .


As for the rubber mounted suggestion ,
If you get a chance to see other IRS set ups ,
they incorperate rubber mounts .

[KobraKarl]

Ronald,

I have a 69 (later) trac-loc and it is very smooth ,but locks up well on acceleration.

You mentioned u-joints rubbing? thats a coincidence, because today I was looking at my rear brake rotors and I noticed some very heavy rounding off of the inboard U-joint ,I've never heard any thing ,but the damage was clearly fresh. I looked with a flash light but couldnt identify anything obvious it could be contacting .......any idea???.............any one ?

[RallySnake]

KobraKarl,

Do NOT drive your car until you find that problem and fix it! It could literally kill you.

Paul

[RallySnake]

KobraKarl,

I had a similar problem with my car. The lower Jaguar arm broke off at the point where it is welded to the yoke. When it let go, the right rear wheel flew up into the fender leaving us sliding along on the frame. We went off the road at 90 mph and over a large hill. My guardian angel got a workout that night!

The two bolts holding the lower arm bracket on are known to come loose and sometimes break. You will want to check these. CWI sells a stainless steel plate that bolts onto the bottom of the two lower brackets and they also have some very strong bolts (Grade 9?) to replace the stock ones with. I cannot recommend them highly enough. CWI is in Orange County, California and they advertise in Kit Car magazine.

Paul

[KobraKarl]

Paul,

Thanks for the warning ,I wasnt going any where until I find the cause.

Even before I bought the car I had heard stories of people killed with these rear ends failing. The two main causes I am told were exactly the one you were fortunate enough to live through,and the other is the failure of a shortened solid half-shaft.

I understand that as the supply of e-type rear suspensions dried up in the late 80's builders began using shortened /rewelded sedan parts ,(possibly yours)in stead,

I do have original (factory lenth) rear suspension parts.

but this u-joint abrasion is a real hair raiser for me...... I wonder if extreme wheel travel could cause this...

[RallySnake]

KobraKarl,

I use that U-Joint to mount the magnets for my rally clocks. I mount the electronic pickup just above them. In fact, I have one on each inner joint. The only thing close to it are the coil overs. Do you see any wear on the springs? Can you move the top of the coilovers outward?

The yoke that broke was from an old Jag sedan. The new ones are from an XKE.

I would definately call CWI. I tracked down an old number I have: 714-642-9807. They have my old broken link on display there along with lots of other problem pieces.

Paul

[wilf leek]

Narrowing of Jag rear ends is commonplace here. Best way to do it is to use some heavy-duty cold drawn seamless tube of about (don't quote me) 11/2 to 2" diameter instead of the original solid halfshaft. Bigger area to weld to the yokes at each end, and a much stronger unit. Use of a seriously competent welder is mandatory.

Also, I am constantly concerned that users of these irs units do not tie the inner lower wishbone pivots into the frame. My own car has this done at each end of the wishbone. Thus failure of those two (and too small to my mind) bolts which clamp the wishbone pivot casting to the diff is also eliminated.
I would not drive a cobra using a jag rear end unless this is done, certainly not at the speeds I commonly enjoy.

To get back to the original question, whilst diff clutch packs can take a while to wear in, they should not lock up the rear. Has it been correctly assembled?
In a light car like your TVR, you could consider reversing some of the clutch plates to reduce the locking action - again something I recommend in a Cobra. Personally I use an open diff for roadwork - makes for a sweeter handling car. Never could understand the desire for lsd in these light cars on the road. Track is a different matter.

Just my 2p's

[KobraKarl]

Wilf ,

I located the rub with the use of a small mirror.....the u-joint is hitting the lower control arm just out board of the wish bone on hard compression.......you guessed it , the lower control arms were put in upside down !!! with the bend upward instead of downward for clearance ! so I will be reversing this.......any suggestions? my bolts do go through the frame.

thanks, Karl

[greenwater]

Wilf,

Interesting reading about reversing the clutch discs to disminish the locking effect. I'm gathering as much infos. on the salisbury as I can get and it sounds they (the diff.) are kind of adjustable at the level of sensibility to do their job in way of adding/retreiving shims to have the belleville plate more or less preloaded. My TVR was rigged in many ways for maximizing straight line performance and very possibly the differential has been arranged accordingly. Hopefully that is the case and thereby shouldn't be a big job bringing it to normal.

LSD or open? I have been very satisfied of my Hawk that had a Powerlock 3.54 in it...not a noise or cling clung from the diff. and excellent road behaviour...but I admit that I've had not ran the same car with an ope one!
regards, Ronald.

[Tom T.]

CWI is up in WA now. I think if you just put the acronym into a search engine you'll find the contact number. If that doesn't work, I can pull it out of my files. Great outfit. Not cheap, but Michael really knows his stuff.

TT

[RallySnake]

KobraKarl,

Wow! I never would have guessed that someone could put the arms together that way. The lower arms are made with a slight bit of toe in. You will notice a tab with a mounting hole that is possibly used for a rear sway bar on your car. When you flip the arms over, you will also have to put the left one on the right side and vice versa so that the sway bar mounts are towards the front of the car.

I fabricated a bracket that the front lower arm bolts to and the other side bolts to the frame. In the rear, I just have a cross beam between the two bolts. I also have the plate attaching the lower bracket together like in the picture below. (Not my car).

Paul

[KobraKarl]

Paul, what is that plate for ?....nice car!