• Advertisement
Xclusively Jaguar
SNG Barratt
David Marks Garages
Make a donation to XJ40.com

Lurch and lumpy gear change on 3.2 xj40

Morgan1
Posts: 150
Joined: Thu Dec 08, 2016 10:45 pm
Location: Aberdare, south Wales

Re: Lurch and lumpy gear change on 3.2 xj40

Postby Morgan1 » Wed Sep 05, 2018 9:35 pm

I'll try doing the quick change from D to R and vice versa. I'll get an assistant in the car and this will give me an opportunity to have a good look underneath. I haven't had a good look at the back end as yet. This will be my next investigation. Thank you for the suggestion.
1992 Jaguar xj6 3.2 litre.
2016 Audi A6 S line.
2016 Ford Fiesta zetec.

Morgan1
Posts: 150
Joined: Thu Dec 08, 2016 10:45 pm
Location: Aberdare, south Wales

Re: Lurch and lumpy gear change on 3.2 xj40

Postby Morgan1 » Tue Apr 30, 2019 7:11 pm

Right then.... I'm up to my you know what's in a rear diff unit strip, clean and rebuild. All parts are off the car and the diff is on the bench. Can anyone tell me if the following is normal? With diff oil in I turn the input hub left and right and there was no play or noise and the two half shafts moved. With no oil in I do the same only there is about 3mm 'play' when moving it left and right and a clonk as it meshes and moves the half shafts. Is this ok? If mot what is wrong?

I have changed the universal joints on both half shafts ( no play in old ones mind) and I'm changing the output shaft bearings as I was getting slight noise on lift off on the accelerator. Would anyone change the input bearings as well just to be sure while it's out or am I spending good money on a poor diff? I haven't checked the drive shaft universal joints yet but have them here and will change them as well.

Image

Image
1992 Jaguar xj6 3.2 litre.
2016 Audi A6 S line.
2016 Ford Fiesta zetec.

Morgan1
Posts: 150
Joined: Thu Dec 08, 2016 10:45 pm
Location: Aberdare, south Wales

Re: Lurch and lumpy gear change on 3.2 xj40

Postby Morgan1 » Thu May 02, 2019 8:50 pm

Hi all, any help would be very much appreciated. If I turn the pinion should it turn left and right without moving the gears in the diff? I can move it a few millimetres. I thought about pinion bearings but that would show as play/ movement in the pinion end but not when turning it? Cheers
1992 Jaguar xj6 3.2 litre.
2016 Audi A6 S line.
2016 Ford Fiesta zetec.

naki_k
Super Moderator
Posts: 28510
Joined: Sun Feb 21, 2010 9:25 pm
Location: Kirton, nr Boston, Lincolnshire

Re: Lurch and lumpy gear change on 3.2 xj40

Postby naki_k » Sat May 04, 2019 10:23 pm

My opinion? Whilst it’s off, it’s worth changing the pinion seal and Input bearings. This is the sort of job you only want to do once.
Most noise from diffs is the bearings on their way out (or gone depending how loud).

With regards to how much play is acceptable, that’s hard to say really. Most diffs I have had off a 40/ 300 have some play on the out put shafts. But how much, I can’t say I have ever really taken much note. Whether your initial issue is the diff play or not again is hard to be sure. But really now, by the time you have spent the time to drop the read subframe, you may as well do everything you can to make it as good as possible.
I think the diff units themselves are very strong. It’s modtly bearings/ seals that ultimately cause issues.
Hopefully it will fix your lurch!
88 3.6 XJ6 PDH/CEM
90 Range Rover Vogue SE 3.9 V8 LPG
91 4.0 XJ6 Manual
92 4.0 XJR Manual
92 4.0 XJR
93 3.2s - 4.0 Manual conv
93 4.0 Sovereign
93 6.0 XJ81 DD6 x2
93 6.0 XJ81 XJ12
94 4.0 XJR
94 4.0 Daimler
96 4.0 X306 XJR
96 4.0 X300 D6
97 4.0 X300 Sport Manual
2000 LR Discovery ES TD5 A
Breaking 40/ 300

Morgan1
Posts: 150
Joined: Thu Dec 08, 2016 10:45 pm
Location: Aberdare, south Wales

Re: Lurch and lumpy gear change on 3.2 xj40

Postby Morgan1 » Sun May 05, 2019 10:41 am

Cheers Naki. Plodding on with it as we speak.... will let everyone know how it goes :shock:
1992 Jaguar xj6 3.2 litre.
2016 Audi A6 S line.
2016 Ford Fiesta zetec.

naki_k
Super Moderator
Posts: 28510
Joined: Sun Feb 21, 2010 9:25 pm
Location: Kirton, nr Boston, Lincolnshire

Re: Lurch and lumpy gear change on 3.2 xj40

Postby naki_k » Mon May 06, 2019 9:10 pm

Morgan1 wrote:Cheers Naki. Plodding on with it as we speak.... will let everyone know how it goes :shock:


Ok good stuff. If you empty out the oil diff, and there’s no signs of metal/ in there (or other signs of damage, then chances are the main components are all fine. You should get away with bearings and seals.
88 3.6 XJ6 PDH/CEM
90 Range Rover Vogue SE 3.9 V8 LPG
91 4.0 XJ6 Manual
92 4.0 XJR Manual
92 4.0 XJR
93 3.2s - 4.0 Manual conv
93 4.0 Sovereign
93 6.0 XJ81 DD6 x2
93 6.0 XJ81 XJ12
94 4.0 XJR
94 4.0 Daimler
96 4.0 X306 XJR
96 4.0 X300 D6
97 4.0 X300 Sport Manual
2000 LR Discovery ES TD5 A
Breaking 40/ 300

Morgan1
Posts: 150
Joined: Thu Dec 08, 2016 10:45 pm
Location: Aberdare, south Wales

Re: Lurch and lumpy gear change on 3.2 xj40

Postby Morgan1 » Tue May 14, 2019 7:42 am

Starting to come together. New half shaft bearings, repainted. New UJ's on half shafts. New subframe mounts, shocks and bushes. Nothing really jumped out as being damaged / faulty to cause the lurch. I've dropped the drive shaft and will change the UJ's. The bush in the centre bearing is very flexible? Anyone think this could be the issue i.e. when I engage D or R the drive shaft might be moving / twisting causing the lurch. Same when changing to 2nd but due to speed not doing it in 3rd and 4th? Seen ne :mrgreen: w ones for £35 so may change it anyway. Some photos of before and after....

Image

Image

Image

Image

Image
1992 Jaguar xj6 3.2 litre.
2016 Audi A6 S line.
2016 Ford Fiesta zetec.

katar83
Posts: 2714
Joined: Tue Aug 23, 2011 11:17 am
Location: Cambridge

Re: Lurch and lumpy gear change on 3.2 xj40

Postby katar83 » Tue May 14, 2019 2:56 pm

Morgan1 wrote:(...) I've dropped the drive shaft and will change the UJ's. The bush in the centre bearing is very flexible? Anyone think this could be the issue i.e. when I engage D or R the drive shaft might be moving / twisting causing the lurch. Same when changing to 2nd but due to speed not doing it in 3rd and 4th? (...)


I have a similar issue, after just replacing a-frame, shocks, springs, uni joints, fitting x308 monobrace that 'lurch' is barely noticeable but still there, I can just about feel it if I tap on gas pedal at 50mph+ or when it sometimes reduces from lets say 3rd to 2nd when slowing down. Which bush in centre bearing is that? I was also thinking maybe gearbox mount or front subframe rear big bushes, difficult to say.
1997, 4.0 LWB X300 - Unlucky car but still a daily driver.
1988, 3.6S XJS - Never ending restoration project.
1994, 3.2S X300 - Accident damaged, October 2015. Gone!
1994, 3.2S XJ40 - Long gone.

Morgan1
Posts: 150
Joined: Thu Dec 08, 2016 10:45 pm
Location: Aberdare, south Wales

Re: Lurch and lumpy gear change on 3.2 xj40

Postby Morgan1 » Wed May 15, 2019 7:34 am

It's not so much a bush but the rubber absorber that surrounds the bearing. Jim 1542 is the part complete. I noticed the rubber around mine was deteriated and cracked. Also very soft when i was moving the prop. Ive changed the gearbox mount ( mine had disolved). If, once this is all back together and the issue is still there I'm going to change the engine mounts to see if it's that. What I will know is that it isn't anything from the rear of the gearbox back!!! :lol:
1992 Jaguar xj6 3.2 litre.
2016 Audi A6 S line.
2016 Ford Fiesta zetec.

katar83
Posts: 2714
Joined: Tue Aug 23, 2011 11:17 am
Location: Cambridge

Re: Lurch and lumpy gear change on 3.2 xj40

Postby katar83 » Wed May 15, 2019 11:09 am

Ah this one. If you decide to swap it(I'm sure it will be worth it) make sure to carefully study this:

http://www.jag-lovers.org/snaps/snap_vi ... 2BlpjIM7kU

I was also thinking jurid coupling, if this is worn out, there should be a bit of extra travel before propshaft engages hence the 'lurch' but its tricky to investigate it without actually removing it :roll:
1997, 4.0 LWB X300 - Unlucky car but still a daily driver.
1988, 3.6S XJS - Never ending restoration project.
1994, 3.2S X300 - Accident damaged, October 2015. Gone!
1994, 3.2S XJ40 - Long gone.