Differential whine

[jimj]

I`ve just developed a whine from the diff. above about 40 mph and not on overrun. Classic symptoms of wear I`m told. The question is: How long before I need to rebuild it?
No fatuous length of string comparisons please !! just facts based on experience .
Jim

[GrUmPyBoDgEr]

Jim,

I'm sticking my neck out here but what sort of answer are you expecting?
Regardless of your "how long's a piece of string" thingy not many of us on here own "Crystal Balls"
Some of us just claim to have big ones.
I hope your car is not a daily drive.
That being the case, this is the best time of year to get the thing pulled to pieces & fixed.
If you take the risk of continued use it's going to let you down somewhere away from home, but what about your own peace of mind? The pleasure of driving an Elan will be marred by the worry of "when is it going to let go?"
Not much help I know & I'm sorry but your question rattled my cage a bit.

Good luck
John

[jimj]

Yes, I realised my "fatuous" comment might ruffle feathers but whilst most responses are helpful, there are some (we all know who) whose wit should start with a "T". Anyway, I`m a grumpy old git.
Re. your advice, I`m of a similar mind but just thought there may be, must be? some members who have put up with a whine for a given number of miles.
Extrapolating, I run a Voight box and love the 5 th gear and light clutch but 1st gear is way too low and I`m thinking that while rebuilding the diff. I may as well go for a taller diff. What does anyone think? and where`s a good place to source the whole diff internals, seals etc?
Thanks,
Jim
P.S. It`s a `67 S3 S/E with, I imagine, the diff. it left the factory with.

[Alex]

Hi Jim,

The question is is the whine from the CWP or bearings? Only way to tell is to take it apart.

I had one fail a while back due to the input shaft bearings failing, causing the rear wheels to lock up - not good! Alternatively, I've got a Morris Minor whose diff has had a small whine for 40,000 miles...

If you do take it out, Fasttrack Bearings do a kit for ?50ish which contains all but the output shaft oil seals (its a Ford kit effectively). When you come to re-build it, you WILL need some good measuring gear - very low range torque wrench (kitchen scales can also be used!) and a vernier to measure the spread of the bearing caps for pre-load.

Hope this helps,

Alex

[miked]

Jim,

You have opened a bit of worm can here!

For ref;

I posted a tail of woe earlier this year which concluded in me spending a lot of money. Perhaps worth reading in the archive. I found a previously quiet but leaky diff' became noisey when overhauled. All new bits save CWP set. It was opened a 2nd time to double check. It did however start to quieten off with use. I can only conclude that the wear in the CWP can be major cause even when set up propely, unless you have very good CWP set. I went for fresh unit by another guy (really nice CWP set & warranty) and put the top quality oil in. This is pretty good but started with a slight whine and is almost silent now after 1000mile. So just watch out as the Elan and plus 2 are cars that you can hear the slightest noise. My point being you could make youself into a more grumpy g*t with best fixing intentions.

Main bit for starter are; Do the input and out put shaft seal leak? When you go under, can you feel lift in the bearings? Also the backlash/play. One of my orginal outputs had quite a lot of play and the bearing was bad, but was quiet.

Mike

I hold my hands up, I only put the diff' nose bit back (and split) and dealt with the output shaft side, bearings and seals part of it myself. I don't have the tools or learning to set a diff' up. Left it to "experts" but still struggled.

[paddy]

My simplistic approach would be to say if the noise came on suddenly, then it's likely a bearing, and best dealt with immediately to avoid either catastrophic failure or damage to other components. If it's come on gradually then wait a bit and see what happens.

Paddy

[GrUmPyBoDgEr]

Just to let you know I'm old & frequently grumpy but I think we are amongst good company here.
My S4 SE has a torquey 185bhp lump in it & it's attached to the original 4 speed g/box.
That combination needed a "long" back axle ratio.
I don't have the tools or experience to do that job.
I can recommend TTR, they did a super job on mine & sourced the required gearing.
Maybe they can sell you the gears if you wan't to do the job yourself.
(They've got some very good gear oil as well, not to mention a nice alloy diff' nose casing)

No I'm not on commision

Cheers
John

[GrUmPyBoDgEr]

Deleted

[bcmc33]

Jim,
You don?t say what your driving or where you?re located. I assume you have a 3.77:1 diff which will make the Voigts? 1st gear a real pain.

I would talk to Tony Thompson. He sources bearings from specific manufacturing locations to meet his racing requirements, and I am sure he could find a 3.54:1 CW&P to help alleviate the 1st gear issue. If you don?t have the knowledge, Tony will rebuild the diff for you.


And fellas - I'm getting very sensitive to OLD. Fart and grumpy are adjectives I can readily accept.

[jimj]

D J Pelly, John, 185 bhp and torquey.............WOW. Amazing !
Because I do about 7,000 miles a year on classic rallies with tests and stuff with full bore starts, I changed to Sue Miller drive shafts. Mindful of correspondence re. fragile output shafts I bought some second hand steel ones. One was a tiny bit marked and OK for 6,000 miles but started leaking very slightly about 1000 miles ago. Seal changed and I thought all was well until this week when the whine SUDDENLY started and yes, the same shaft is weeping. I was thinking a lack of oil may have caused some damage but do you think it`s just this shaft and bearing causing the whine? I have topped up the oil.
Jim

[Tonyw]

Hi all,

Differential whine is usually cause by a miss-alignment of the crown wheel and pinion, sorry if I am stating the obvious, a whine by it's self is not necessarily a problem but if left for any period will be almost impossible to remove when the differential is overhauled as the wear marks will be entrenched on the gears. If the noise has started all of a sudden I would be suspecting the collapsible spacer having lost preload on the pinion bearings. As far as how long it would last I do not think any of us could provide a satisfactory answer. These differentials are not hard to come by I would suggest you find a second hand one of the correct ratio, have it overhauled and ready to install when you cannot put up with the noise or it fails.

Tony W

[gordonlund]

The best optional diff for any Elan is the Ford Escort Mexico 3.54:1. A little taller than the std 3.77 but much stronger and if in a light on song baby Elan will not make much differance but will be a lot quieter in lowering engine revs for any given speed. In my +2 the off the line acceleration is a little slower but once on the move you hardly notice. Makes for much more comfortable cruising and a marginal increase in fuel consumption efficiency. The Ford/hotrod fraternaty prefare the 3.77 dif which is now getting hard to get hold of and many will swap a good 3.54 for a genuine 3.77. Thats how I got mine. Try the Formula 2 banger racers.

Type "differential" in the search box, there are loads of links in here, if you have the time.

Gordon

[jimj]

So............I`ve replaced the output shaft bearings, and still the whine is there; Only over about 40 m.p.h. not at all when you take it out of gear, even at 70 m.p.h. and only when feathering the throttle or accelerating.
Am I right in thinking it has to be the diff. internals? It can`t be a rear wheel bearing, can it?
Jim

[miked]

Jim,

I had the same, even after rebuild. I dont think it takes much of a wear pattern on the CWP or poor adjustment to give you that noise. If you have checked the rear wheel bearing for play and they have none and feel right I would not think it would be them. I have heard about people getting a noise from the inner wheel bearing dirt shield as it catches. Usually goes with squirt of WD. However, it would be at all speeds.

I found that the noise was coming from that area so you knew it was from the diif' by just by leaning back.
In the end you become paranoid about diff noise. As I said early I had one rebuilt and opened it twice. All in spec' but still made your type of noise. Even the really mint fresh one I now have did it for a while until it bedded in. The idea about getting a good one prepared sounds right to me. That is what I would. I did got to the far end of a fart making sure nothing was touching and all may shafts were balance etc but on reflection the whine was distinctively a diff one on feathered and slight throttle opening at 30 - 40mph.

Mike

[seaandmoor]

It is difficult,
my whine started some time ago (after fitting Voigts box and Miller solid drive shafts curiously - are these combinations overloading the diff assembly?) and the local lotus garage said difficult to say until it gets worse... it did seem to be slighty worse on one bend as opposed to another and did start suddenly. Not so noticeable freewheeling though.

I think one day I'll end up at TTR's door aswell