5 Speed 365 Gearbox

[TCS4605R]

I had my 365 fail some years ago - the metal cage around one of the diff bearing broke - the diff gears ground up the pieces.  Ended until replacing some gears, all syncros, bearings, seals, O-rings, etc. reset the ring and pinion backlash and the side bearing preloads.  Take your time and, with the shop manual, you can put it back together.

Tom
74 TCS

[Chuck Nukem]

I had my 365 fail some years ago - the metal cage around one of the diff bearing broke - the diff gears ground up the pieces.  Ended until replacing some gears, all syncros, bearings, seals, O-rings, etc. reset the ring and pinion backlash and the side bearing preloads.  Take your time and, with the shop manual, you can put it back together.

Tom
74 TCS

Tom,

Do you have a source for 365 gearsets you could share?

[jbcollier]

NOS 365 gearsets = pure unobtainium.  Find used or not at all.  That's why there's been a raft of NG3 installations  -- a stronger trans but nowhere near as nice gear ratios.

[GavinT]

Yes . . unobtainium.
There's a guy the Renault & Alpine people use who I think is Scottish . . and not cheap.

The Renault guys do all sorts of things like stuffing the 336 innards into a R8 gearbox for the extra strength. I recall the Scott even does work like extending a 352 main shaft to fit into a 365 tranny. Actually, a 365 with a 3.55 diff would be brilliant, I reckon.

I'm blowed if I can remember his name, but I'll work on that.

[Lotuswins]

I too had a noise, weird that it only happened on light deceleration.  I wiggled the axles and u-joints which all seemed tight so went into the gearbox.  Nothing.  It turned out to be the outboard bearing on the right carrier had shed its cage.  Apparently when I assembled it, the spacer cocked slightly causing the failure (15kmiles on it before failure)  The use of a double row ball bearing on the inside of the carrier kept everything really tight when trying to locate the fault. 

So, how many miles on the axle bearings/u-joints?  Did you install an aluminum flywheel on the restoration? Did you reset the pinion/crown backlash at that time?  Who set up the shim pack for the inner yokes? Pins still in, and no fretting observed?  Any leakage around the yokes?

Hope it all ends well!! 

Jerry Rude
4005R

[TCS4605R]

Chuck - some of the parts came from Dave Bean and some from a fellow in Maine who is no longer in business - can’t remember his name but he went on to write a number of books - his real calling evidently.

Tom

[Certified Lotus]

Chris, have you checked the 4 bolts on the inside of the rear wheel bearing housing to see if they have come loose? There is a very tight tolerance and if the have started to loosen they can hit part of the half shaft assembly and cause a clunking sound with each revolution of the wheel. That would be the easiest thing to check before taking the transaxle out.

[TheKid#9]

Chris, have you checked the 4 bolts on the inside of the rear wheel bearing housing to see if they have come loose? There is a very tight tolerance and if the have started to loosen they can hit part of the half shaft assembly and cause a clunking sound with each revolution of the wheel. That would be the easiest thing to check before taking the transaxle out.

Hey Glen,
I have not checked that... Might do that this weekend or next weekend. I hope that is the problem because I really do not want to take everything apart. I'll keep you guys updated.

[TheKid#9]

Took a quick look tonight and it doesn't seem that those four bolts are loose... I have already put some feelers out there for a new gearbox just in case. 

[jbcollier]

Drain the gearbox oil.  If it's clean, it's not the gearbox.

[TheKid#9]

We drained the gearbox oil and only found one metal piece (Very Small) and a couple filings. We feel reasonable about the gearbox and believe it is the wheel bearing that we know is bad. We will work on fixing the bearing before we take the gearbox out.

It only happens when the car is driven and gets hot. My dad thinks the wheel bearing gets hot and then has a problem. We are working on figuring out the issue.

[jbcollier]

That's metal?

I would pull the transaxle apart and see where it came from.  Remember, parts are hard to find so you want to catch things early.

Loud, gawd-awful clunking from the transaxle and suspension should not be temperature related.  Worse, perhaps, but not quiet and then loud.

[TheKid#9]

It is not the gearbox... Thank God!
My mechanic found that the stub axle and everything in the rear hub was damaged. It seems that the bearing was for the TC and not for the TCS, the numbers did not match up. Ordered parts from Ray to have it all fixed. Should be back on the road sooner than later.

[BDA]

Great, Kid! It sounds like you will get your baby fixed up and on the road soon!

[TheKid#9]

Indeed! Looking to have it back soon. Since it’s been down for awhile I’ve been enjoying my other Lotus I picked up earlier this year... Enjoy!