Changing Upper Diff Mounts

[au-yt]

Hi All
This is probably an Elan 101 question and been discussed however, can the upper diff mounts be changed with removing the diff itself?
I have changed these decades ago but that car I had the body off the chassis.
Cheers
Graeme

[patrics]

Hi,
Yes the are removed through the boot so not a bad job

Regards
Steve

[MickG]

Hi Graeme,
You will need and assistant to help with the bolts; or have extremely long arms.
Regards Mick G

[alan]

i suggest you make a packing piece from wood to slide between the bottom of diff and chassis. This will keep the diff in place and you can change the mounts one at a time. If fitting standard mounts "frustacones" keep spacer washers in original postions.
good luck Alan

[au-yt]

Guys Thanks for the advice,
Alan you make an interesting comment about the spacers and may have hit on something.
The Mounts look fine but the diff is siting on the chassis.
Any one know the clearance that should be under the diff at a Pint or closest point?
Cheers
Graeme

[alan]

i hope the chassis is not damaged where someone has put a trolley jack just Under the diff and bent the chassis.
It will not be the first time this has happened

[Quart Meg Miles]

Hi Graeme,
You will need an assistant to help with the bolts; or have extremely long arms.
Regards Mick G

Na, a few bits of wood keep the diff in position and a ring or open ended spanner can be perched on the bolt head (which is at the boot end on my car) while the nut is wound on.

You must retain one thick spacer between the diff and each Frustacone so if you have two take one out. I can't see why two are necessary unless the diff is hitting the top of the chassis; lets hope Alan's theory isn't correct or you will need a very large hammer with the diff out. And you don't want to take that out if you can avoid it, believe me.

BTW, which model is your car?

[terryp]

Just one little thing, if you have or are thinking about some form of solid driveshalfs then its better to invest in the TTR diff mounts as the solid driveshafts put more pressure on the diff mounts.

Terry

[rgh0]

I agree that the lower torque rod rubbers probably see more shock load with solid drive shafts and they need more regular replacement as they also get soaked in oil compared to the top Frustacon mounts. The top mounts don't see much of the wheel torque load as the diff pivots on them so not really affected by solid drive shafts installation. They do resist the prop shaft torque load but this is much smaller.

In any case 30 years of racing with solid drive shafts and many many drop the clutch starts and 180 hp and sticky tyres and the standard top diff mounts in my Elan were perfect when I removed the body recently but then maybe they were better made 30 years ago.. I think I have replaced the lower torque rod rubbers twice in the last 30 years once about 15 years ago and one about a year ago. I have a spare set of the TTR torque rod poly mounts here if need but so far I have stuck with the standard components

cheers
Rohan

[alan]

imho it is always a good idea to fit the Bracing bar on the diff which was a mod for the Big Valve engined cars

[au-yt]

Great insight Guys I will investigate further, damage to chassis due trolley jack. I have a new set set of solid shafts that have not been fitted. and I also have 3 (shame) new donuts still in the lotus packaging. Debates out on that.
Are these the diff torque bushes?
TTRFD 005 DIFF TORQUE ROD LOWER BUSHES AND CUPS EXTRA HEAVY DUTY KIT
http://www.tonythompsonracing.co.uk/pricelist.pdf

Graeme

[rgh0]

yes
cheers
Rohan

[patrics]

Hi,
I fitted TTR torque rod bushes but found them to be the wrong length and I ran out of screw thread before properly compressing the bush - fitted some standard ones from Paul Matty and all okay.
I'm sure the TTR one are okay now but mine weren't.
When fitting these rods do a trail fit without attaching to the chassis then pull and push hard on the rod to check for play
Hope that helps
Steve

[au-yt]

Hi Steve
I am amazed at the various small variation with the cars, so the issue with the bushes doesn't surprise me.

Some times with lots of things with these cars if there was design setup data available with more detail than the Factory book we would be better off, but that's the nature of "hand made cars" they are all subtly different.

I still haven't tackled the mount issue yet but will shortly and thanks to everyone's advise some what more informed.

Best Regards
Graeme

[au-yt]

Interesting I have just been reading the work shop manual and there is at the back of Section R, R7
Differential unit replacement (Sprint).
It refers to section R2 for instructions there is a mention of a clearance to the cross member at the top, but no pictorial representation as to what that means.
In R7 you can remove all the two inch washers to get this clearance, as the spreader bar does the same thing as a 2" washer.
As my car is a sprint can some one elaborate on what this clearance means please.

Graeme