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juddering in reverse...

PostPosted: Wed Sep 13, 2006 9:59 pm
by thor
Why?
Even with a very modest pressure on the accelerator it seems very juddery, i.e. when correcting my parking in my alotted garage space.. It does seem much smoother in 1st so then it can't be the clutch can it? Broken cogs on the reverse? clutch?

very annoying in my luckily otherwise lovely (touch wood) +2S

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 3:01 am
by 1964 S1
It could be a broken motor or trans mount, or a rotoflex starting to go. The drivetrain torques up differently in reverse, the only other thing that comes to mind is oil on the clutch. If it was broken cogs (unlikely) I'd think you'd feel it in the lever.

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 8:02 am
by thor
aha! But surely I'd feel it in first gear?
What's the best inspection procedure and fault finding for the donuts?

Hoping it's not this, or at least if it is it'll hold until I put it away for the winter, as I'm planning a driveshaft conversion for the spring. No way I'm trying the complex donut changing now.. :-)

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 9:01 am
by Robbie693
Well, just to trow a spanner in the works, :wink: , I did the driveshaft conversion recently and it still judders in reverse...

I tend to think it's the oil on the clutch - every Plus 2 I've seen seems to leak from the rear crank oil seal, including the last one I had, which also juddered. It doesn't seem to affect take off in first though for some reason

Robbie

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 9:50 am
by rgh0
The one time I had juddering in reverse it was a broken top diff mount bolt. So have a close look at these

regards
Rohan

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 10:41 am
by thor
hm.. food for thought. IF it's oil on the clutch, would this dissipate with more use? It hasn't had a lot of use the last month and a half, or is this a completely silly theory? How easiest to gain access to the top diff bolt then?

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 11:20 am
by types26/36
[quote="thor" IF it's oil on the clutch, would this dissipate with more use?[/quote]

Unlikely as it will get absorbed into the friction material and will get worse or if more oil gets on it then it will probably start slipping :cry:
As has been sugested check the mountings first ......you just might be lucky :D
Elans do seem prone to the reverse judder and my Sprint has started doing it but I dont drive many miles in reverse :lol: so I'll worry about it at a later stage........actually I dont do many miles in any gear :lol:

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 1:40 pm
by triumphelan
I had a "judder " whilst pulling away inlow revs,not when "boy racing " ,I changed the engine mounts ,the drive shafts to Tony Tompson,all rear end bushes and finally the clutch because I susspected oil ingress ,it was clean
I still have a judder at slow speed whilst pulling away if I raise the revs slightly it pulls away with no judder
I live with it

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 2:02 pm
by thor
hm.. I'll try to get to the diff top mount to check it, and try the car again tonight just to check the difference in revs versus careful clutching or not. Come to think of it I had a similar problem on a GT6 four years ago, which also had donuts, so maybe I'm not assimilated back to the donut principle yet, after a couple of years now with the +2.
Surely it can just be the donuts winding up in case of to many revs, to quick on the clutch?

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 2:07 pm
by Garibaldi
I'm not advocating this, as it is a less than proper repair, but I've known people to check for oil on clutch disks by spraying carb or brake cleaner on the clutch in large quantities. Before I'm chastized for this, it is not a suggestion, merely a datapoint. My knowledge of Loti is scant, at best. I'm sure someone with infinitely greater understanding will chime in and tell me what a stupid remark I've made. That's fine with me. I'm here to learn.

GP

thor wrote:hm.. food for thought. IF it's oil on the clutch, would this dissipate with more use? It hasn't had a lot of use the last month and a half, or is this a completely silly theory? How easiest to gain access to the top diff bolt then?

Re: juddering in reverse...

PostPosted: Thu Sep 14, 2006 9:10 pm
by tower of strength
unlikely to be oil on the clutch as it would do this all of the time, could be soft or broken springs in the clutch drive plate, I had this on a Spitfire, changed engine and gearbox mounts, U/Js gave up and changed the clutch and found the springs all loose and rattly, new clutch cured the problem!

Re: juddering in reverse...

PostPosted: Fri Sep 15, 2006 11:58 am
by elansprint71
Top differential mounts- a well-documented "fault". New diff mounts are rubbish due to H&S issues with something nasty which used to be in the old rubber but now cannot be used.
Solution: buy Tony Thompson's heavy duty diff mounts, not cheap but, as usual, excellent.

Been there, done that. :twisted:

Cheers,
Pete.

Re: juddering in reverse...

PostPosted: Fri Sep 15, 2006 12:18 pm
by thor
Ah, is this easy to get to/check in my Spyder frame? Haven't lifted it up and been under for a while..

Re: juddering in reverse...

PostPosted: Fri Sep 15, 2006 2:25 pm
by stuartgb100
Was easy enough on my early spyder-chassis Sprint.

Found best access was gained by jacking at the rear, then putting a full-width 6 x 4 timber under the back end of the cills, with the ends under the rear of the cills being supported on blocks. Also the centre. Then remove the jack.

Also make sure the rear driveshafts are not at full droop.

Regards,
Stuart.

Re: juddering in reverse...

PostPosted: Sat Sep 16, 2006 10:17 pm
by chrishewett
I have had new gearbox ,clutch, diff,diff mountings, donuts, engine rebuild to name but a few. Still have a bit of judder in reverse. I think just live with it.
Chris