X308 XJR knackered rear Diff
#22
02-23-2012, 11:10 PM
This Jaguar is sooo not my favourite car right now 
Driving to work one day I heard a nasty metalic noise- as if something from the underside had fallen off. I see nothing under the car. After removing the rear wheels, I see nothing untoward. When driving the car- there is a loud knocking noise that increase with vehicle speed and changes tone whether under load or not.
I sucked out the oil from the diff and checked it and there was no metal particles. I stuck a magnet in the diff to see if I could find any metal bits- nothing. I stuck the magnet into the transparent container with the oil diff oil to check for debris- nothing. I checked for wheel bearing play- nothing. I checked the drive shaft U joints- and they seem ok. I drive the rear wheel with the rear of the car in the air and the noise is certainly there.
At this stage I no longer have time to devote to this car. I give it to Eurotoys in Elgin to look at- and he suspects the diff.
I found out that the differential was already changed once in 2006 under waranty.
I talk to an old friend from Jag-Whitley who owns an X308 XJR and he's had similar issues. Another friend- who's ex Jaguar- filled me in on the diff. He worked in that department. He said that the decision to go for the 14 HU unit (as fitted to the X308) and carry this unit to the supercharged vehicle was ludicrous. He had opposed this decision but it was made by passionless folks who didn't care at all and just wanted to get the product out on time.
He said that for the XK180 concept car the older offset type 15 HU diff was used with powerlock- and its vastly stronger. He said on the 14 HU the teeth just fall off the pinion and the safety factors were just not high enough. This really upsets me. I don't see the point in getting another 14 HU unit. Waste of time cost cut engineering. On the otherhand, I don't want to fit a powerlock 15 Hu 3.58 ratio and spend $2K reprogramming the TCM.
I've been doing my research and the old hot rodders used to use the salisbury 4 HU units (as fitted to old series 3s and XJS') which had Dana 44 gear ratio interchangeability. There are plenty of Dana 44 gear sets availiable- including the required 3.07 ratio.
I asked my ex Whitley chum if I can use the gears from the older series 3 type diffs (4HU) into a 15 HU. He said no- because the XJS, old series 3 and even the Aston DB7 use a U joint on the prop shaft and the XJ40, X300 and even X308 use a jurid elastic coupling. I don't understand this exactly- becuase it seems to me that the Dana 44 gear sets have 26 splines as does the X308 prop shaft.
These websites have indicated that interchanging Xj40/X300 15 HU style diffs are possible.
REAR END SERVICE FOR CLASSIC JAGUARS
And this site even believes that the Salisbury/Dana44 style gears will still fit into the 15 HU casing.
Independent Rear Suspension Forum / XJ40 IRS - Boardhost Free Forums
And here-
XJ40 Powerlock
Russel-Rams post indiciated a high level of interchangeability.
I'm still doing research but welcome any other further useful information
Driving to work one day I heard a nasty metalic noise- as if something from the underside had fallen off. I see nothing under the car. After removing the rear wheels, I see nothing untoward. When driving the car- there is a loud knocking noise that increase with vehicle speed and changes tone whether under load or not.
I sucked out the oil from the diff and checked it and there was no metal particles. I stuck a magnet in the diff to see if I could find any metal bits- nothing. I stuck the magnet into the transparent container with the oil diff oil to check for debris- nothing. I checked for wheel bearing play- nothing. I checked the drive shaft U joints- and they seem ok. I drive the rear wheel with the rear of the car in the air and the noise is certainly there.
At this stage I no longer have time to devote to this car. I give it to Eurotoys in Elgin to look at- and he suspects the diff.
I found out that the differential was already changed once in 2006 under waranty.
I talk to an old friend from Jag-Whitley who owns an X308 XJR and he's had similar issues. Another friend- who's ex Jaguar- filled me in on the diff. He worked in that department. He said that the decision to go for the 14 HU unit (as fitted to the X308) and carry this unit to the supercharged vehicle was ludicrous. He had opposed this decision but it was made by passionless folks who didn't care at all and just wanted to get the product out on time.
He said that for the XK180 concept car the older offset type 15 HU diff was used with powerlock- and its vastly stronger. He said on the 14 HU the teeth just fall off the pinion and the safety factors were just not high enough. This really upsets me. I don't see the point in getting another 14 HU unit. Waste of time cost cut engineering. On the otherhand, I don't want to fit a powerlock 15 Hu 3.58 ratio and spend $2K reprogramming the TCM.
I've been doing my research and the old hot rodders used to use the salisbury 4 HU units (as fitted to old series 3s and XJS') which had Dana 44 gear ratio interchangeability. There are plenty of Dana 44 gear sets availiable- including the required 3.07 ratio.
I asked my ex Whitley chum if I can use the gears from the older series 3 type diffs (4HU) into a 15 HU. He said no- because the XJS, old series 3 and even the Aston DB7 use a U joint on the prop shaft and the XJ40, X300 and even X308 use a jurid elastic coupling. I don't understand this exactly- becuase it seems to me that the Dana 44 gear sets have 26 splines as does the X308 prop shaft.
These websites have indicated that interchanging Xj40/X300 15 HU style diffs are possible.
REAR END SERVICE FOR CLASSIC JAGUARS
And this site even believes that the Salisbury/Dana44 style gears will still fit into the 15 HU casing.
Independent Rear Suspension Forum / XJ40 IRS - Boardhost Free Forums
And here-
XJ40 Powerlock
Russel-Rams post indiciated a high level of interchangeability.
I'm still doing research but welcome any other further useful information
#23
02-23-2012, 11:21 PM
The X300 XJ6/XJR/XJ12 do not have a speed sensor that would pick up the pinion/transmission output rotational speed - like most older Jaguars and other cars. Instead they use the ABS sensors (I think left rear sensor) to get the vehicle speed. This means that changing differential ratios (but not tire size) does not affect the indicated speed. (Even the XJ40s used an exciter wheel/pickup combo on the OUTPUT shafts, not the transmission/pinion).
So, if the X308 also uses one of the ABS sensors, then changing the differential ration should not be an issue.
So the only problem I could see is that the ECU/PCM would see a mismatch between road speed and engine RPMs for each gear. On the X300 (and likely XJ40) is does not matter, but you might want to research this for the X308.
So, if the X308 also uses one of the ABS sensors, then changing the differential ration should not be an issue.
So the only problem I could see is that the ECU/PCM would see a mismatch between road speed and engine RPMs for each gear. On the X300 (and likely XJ40) is does not matter, but you might want to research this for the X308.
Good info. I was going to suggest using a speedcal to fix the speedo signal, but if its wheel driven, its all good for ratio changes.
#24
02-23-2012, 11:43 PM
#25
02-24-2012, 01:31 AM
I'm sorry Adam, Ive been away for a while, been rebuilding my Challenger. My Jag is still in the garage with broken diff. I have a powerlok 15HU 3.58 that I still intend to rebuild when I get around to it, with 3.07 dana insert if I can do something about the flange to the prop shaft.
Please keep me informed about what you do
Please keep me informed about what you do
#26
02-24-2012, 01:40 AM
I'm sorry Adam, Ive been away for a while, been rebuilding my Challenger. My Jag is still in the garage with broken diff. I have a powerlok 15HU 3.58 that I still intend to rebuild when I get around to it, with 3.07 dana insert if I can do something about the flange to the prop shaft.
Please keep me informed about what you do
Please keep me informed about what you do
#27
02-24-2012, 09:50 PM
Adam, the 3.58 15 HU diff (with a change in triangular plate) is a direct fit into the X308. The issue as you know is the TCM problem. I myself also prefer the taller gearing that the 3.07 affords.
The Dana 44 crown wheel and pinion is designed to fit the even older 4HU diff and that has a different flange to mate up to the prop or drive shaft.
Probably not an insurmountable problem- would have to look deeper
The Dana 44 crown wheel and pinion is designed to fit the even older 4HU diff and that has a different flange to mate up to the prop or drive shaft.
Probably not an insurmountable problem- would have to look deeper
#29
06-24-2012, 01:55 PM
Adam
#30
10-02-2013, 04:06 PM
#31
05-26-2014, 03:49 AM
I noticed that SC Parts Group are now supplying an upgraded crown wheel and pinion for the Salisbury type differential:
Forged from high grade chromium molybdenum steel:
3.07:1 ratio (teeth: 17/52)
Jaguar XJ6 and XJ12 Series I, II and III fitted with GKN differential (1961-74) • E-Type Series 1, 2 and 3 (1961-74)
Crown wheel and pinion - Page 1 - SC Parts Group Ltd
Would this fit ?
Forged from high grade chromium molybdenum steel:
3.07:1 ratio (teeth: 17/52)
Jaguar XJ6 and XJ12 Series I, II and III fitted with GKN differential (1961-74) • E-Type Series 1, 2 and 3 (1961-74)
Crown wheel and pinion - Page 1 - SC Parts Group Ltd
Would this fit ?
#32
12-03-2014, 07:21 PM
I noticed that SC Parts Group are now supplying an upgraded crown wheel and pinion for the Salisbury type differential:
Forged from high grade chromium molybdenum steel:
3.07:1 ratio (teeth: 17/52)
Jaguar XJ6 and XJ12 Series I, II and III fitted with GKN differential (1961-74) • E-Type Series 1, 2 and 3 (1961-74)
Crown wheel and pinion - Page 1 - SC Parts Group Ltd
Would this fit ?
Forged from high grade chromium molybdenum steel:
3.07:1 ratio (teeth: 17/52)
Jaguar XJ6 and XJ12 Series I, II and III fitted with GKN differential (1961-74) • E-Type Series 1, 2 and 3 (1961-74)
Crown wheel and pinion - Page 1 - SC Parts Group Ltd
Would this fit ?
No, the problem I'm encountering after examination of components and much research is that that Series 1, 2 and 3 GKN diff is a 4 HU unit (as fitted to old E types etc)- it is a strong crown wheel and pinion but the 10 bolts that bolt it to the carrier are 7/16th size.
The Dana 44 was always a 3/8th size. The later 15 HU unit I'm seeing now as fitted to late XJ40s and X300s has a 10 bolts of 15mms that secure the crown wheel to the carrier.
Both Dana 44 , 4HU an 15 HU seem to be of 19 spline design at the carrier/stub shaft end. The later (weak) 14 HU is of a 25 spline design.
#33
12-03-2014, 08:26 PM
Veteran Member
Is 15mm the thread size or the bolt hex head?
15mm translates to 0.5906 inches, whereas 3/8 inches as used by Dana is 0.375 inches,
and 7/16 inches is 0.4375 inches.
The writeups outside of JF are sometimes confusing when it comes to the input when
converting to Dana ring and pinions. The answer is simple. The Dana pinion will require
a Chevy yoke. The Chevy yoke will have a conventional u-joint. The u-joint on the
Jaguar driveshaft is also a Chevy u-joint. Remove the coupling at the u-joint, and
connect the Chevy yoke to the drivesahft by means of the u-joint omitting the
jurid coupling section.
The most available 19 spline Dana style LSD to fit is made by Auburn and costs
about $350'ish. Note that it is non-rebuildable.
A 19 spline Dana fit is also available as various lockers including a Detroit Locker
at $480'ish.
Lockers are not recommended on the street. But, they are available.
These differentials are 3/8 inch, so the choice is Jaguar gears with the differential
holes enlarged to 29/32, a set of bolt adapters from Curt someone or other in
California, or Dana gears and Dana differential with Chevy yoke.
The non Jaguar differentials result in the use of cheaper install parts like bearings.
Either way, the output shafts will fit without modification due to the 19 spline
configuration.
++
15mm translates to 0.5906 inches, whereas 3/8 inches as used by Dana is 0.375 inches,
and 7/16 inches is 0.4375 inches.
The writeups outside of JF are sometimes confusing when it comes to the input when
converting to Dana ring and pinions. The answer is simple. The Dana pinion will require
a Chevy yoke. The Chevy yoke will have a conventional u-joint. The u-joint on the
Jaguar driveshaft is also a Chevy u-joint. Remove the coupling at the u-joint, and
connect the Chevy yoke to the drivesahft by means of the u-joint omitting the
jurid coupling section.
The most available 19 spline Dana style LSD to fit is made by Auburn and costs
about $350'ish. Note that it is non-rebuildable.
A 19 spline Dana fit is also available as various lockers including a Detroit Locker
at $480'ish.
Lockers are not recommended on the street. But, they are available.
These differentials are 3/8 inch, so the choice is Jaguar gears with the differential
holes enlarged to 29/32, a set of bolt adapters from Curt someone or other in
California, or Dana gears and Dana differential with Chevy yoke.
The non Jaguar differentials result in the use of cheaper install parts like bearings.
Either way, the output shafts will fit without modification due to the 19 spline
configuration.
++
Last edited by plums; 12-03-2014 at 08:34 PM.
#34
12-03-2014, 08:35 PM
Veteran Member
Join Date: Nov 2006
Location: Glasgow, Scotland UK
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These are the guys responsible for the chain design of the Jaguar V8
Tsubakimoto Chain Co. - industrial roller chain, conveyor chain, power transmission components & materials handling systems
They're called 'silent chains' and their pitch is such that they produce very little whining. You could learn from their example.
Tsubakimoto Chain Co. - industrial roller chain, conveyor chain, power transmission components & materials handling systems
They're called 'silent chains' and their pitch is such that they produce very little whining. You could learn from their example.
Made me laugh
In my job as sales to construction companies, ( parts for asphalt plants ) I supply lots and lots of chain
Chain for elevators, mixers, dryers, small chain, simplex, duplex and triplex as well as some that are 9" pitch or bigger
In the past I have dealt with Tsubaki and supplied their chain.
I actually looked into this in the past and identified the tensioner chain, something like 06B1 if memory serves
#35
12-13-2014, 02:06 PM
Veteran Member
Since this thread has come back to life. Count Iblis, why don't you consider putting in a Lincoln Mark 8 pumpkin. You can fit any Ford 8.8 LSD and the Ford 8.8 will let you use any gearing you want. Relatively easy to do. See other threads on the forum. If you build it up with 31 splines, it will be good for 600+ HP. Stock 26 splines are good for 400+ HP.
#36
12-13-2014, 05:08 PM
Veteran Member
#37
12-13-2014, 06:01 PM
Veteran Member
My bad. I though the car is a 2004-2009 XJ. X350/X358. This gen has the subframe that can accept a Mark 8 differential.
Last edited by Tijoe; 12-13-2014 at 06:01 PM. Reason: spelling
#38
12-13-2014, 08:55 PM
Veteran Member
#39
06-07-2015, 08:02 PM
I have no idea if this would be of any help: Looking at ways to waste money on ebay i came across...
Maserati Quattroporte Series III 3 Torsen Sensitork Differential Rear End | eBay
That looks almost exactly like a jag rear (except for the Maserati parts). The carrier looks exactly like a 4hu. Would be very cool if the Maserati diff was a 19 spline dana 44 torsen!
The vented disk's would be a great talking point on an E-Type or Xjs.
Maserati Quattroporte Series III 3 Torsen Sensitork Differential Rear End | eBay
That looks almost exactly like a jag rear (except for the Maserati parts). The carrier looks exactly like a 4hu. Would be very cool if the Maserati diff was a 19 spline dana 44 torsen!
The vented disk's would be a great talking point on an E-Type or Xjs.
#40
06-07-2015, 11:22 PM
I have no idea if this would be of any help: Looking at ways to waste money on ebay i came across...
Maserati Quattroporte Series III 3 Torsen Sensitork Differential Rear End | eBay
That looks almost exactly like a jag rear (except for the Maserati parts). The carrier looks exactly like a 4hu. Would be very cool if the Maserati diff was a 19 spline dana 44 torsen!
The vented disk's would be a great talking point on an E-Type or Xjs.
Maserati Quattroporte Series III 3 Torsen Sensitork Differential Rear End | eBay
That looks almost exactly like a jag rear (except for the Maserati parts). The carrier looks exactly like a 4hu. Would be very cool if the Maserati diff was a 19 spline dana 44 torsen!
The vented disk's would be a great talking point on an E-Type or Xjs.
That really does look like a Jag rear end!
I know the old Massers basically copied the contemporary E12 BMW 5 series under pinnings such that the shocks were pretty much interchangeable but I had no idea they copied the Jag rear end (just like the 60s Corvette did).
I have the engineering drawings ready and am getting stub shafts made now- out of 4340- heat treated. I'm switching to 30 spline output shafts. This allows me to use Dana 44 crown wheel and pinions and a Torsen T2-R-one of the best high performance traction devices out there and very durable. The Dana 44 commonality allows the use of very strong gears from Nitro gear and Yukon gear.
The trick is to get an extension nose piece made at the companion flange that inserts into the jurid coupling to keep it centred, as the stock 14 and 15 HU pinion does (but the Dana 44 has a shorter nose as its applications usually use a U joint)
This promises to be a very robust rear end- with Dana 44 internals it will certainly rival the much fabled Ford 8.8 inch