5 speed leak

[rjbaren]

My twin cam special 5 speed has a drip from the trans.  It was rebuilt by a Lotus dealer and has since covered 1500 miles.  I have replaced the rear seal on the shifter rod twice and the second time I used a 1mm smaller bore seal and it made no difference.  I top up the fluis every month or two and I keep cardboard under the car to soak up the gear lube.

Is there a chance the trans is leaking from the joint in the case where the left and right halves meet? 

[FourLoti]

No experience with case seam leaks, but my 5-speed was leaking from two (3) sources. First, the speedometer cable drive gear fitting, and the other two were the left and right driveshaft output seals/o-rings. Seema as if any of those could have been disturbed or maladjusted in a rebuild?

Maybe hose off the box with a can of brake cleaner and then wait to see where the next drip(s) come from? They make UV detection dye that is supposed to be compatible with gear lube, but hopefully it will be obvious based on where the spots develop on the cardboard.

Ron

[BDA]

One would hope it's not leaking from the case joint!!! Of course, that's always possible. It's very common to leak from the control shaft where shift inputs enter the case.

If your tranny is leaking from the finned adjusting nut, there are instructions elsewhere that describe how to replace the seal or o-ring. If it is the o-ring, one method that I don't think anybody has mentioned is to smear Hylomar on the threads. When I rebuilt my NG3, I ordered some new o-rings and got the wrong size  . My o-rings were probably just find as I hadn't had any leaks there but I figured the Hylomar would make double dog sure it wouldn't leak from the threads. Before loosening the finned nut, mark its position relative to the case and count the number of turns to take it off so you can get it back to the same orientation. Do one side at a time. Actually, I think snugging the finned nut will be all you really need to know but it's best to mark and count the turns.

[GavinT]

rjbaren,

Check the side to side play of the shaft. The seal won't tolerate much play without leaking.

Case joint leaks are less common. I wonder if you couldn't create a temporary plasticine dam under the transmission so as to form a barrier where the oil will drop straight down from the shaft and not migrate back under the gearbox? Just a thought.

[4129R]

I think there was a quote from Colin Chapman "If it didn't leak oil from somewhere, it would not be a Lotus.

L eaks
O il
T hrough
U nusual
S ources.

[cazman]

I have a similar problem. A guy that rebuilds our unique trans gave me the clue. He said that over the years people back into curbs and things and bend the shifter rod. That is what creates the leak from that back rod seal. He always checks that rod and trues it up or replaces it, but many people do not check it because it looks fine.

So after I replaced the seal with no resolve and he gave me this clue, I decided to park the Europa differently as an experiment. I always left it in 1st gear when parked and it leaked. I tried parking it in different gears and behold if I keep it in neutral - no leak! I guess it depends where the rod is bent.

[Footer]

I have a similar leak in my 5 speed.  I located the leak at the rocking lever shaft and decided to disassemble it.  When I did there was no O ring present, #34 below.  Simple enough, so I secured the appropriate O ring and installed it.  Now it continues to leak from that point and I don’t have a solution, yet.
Good luck with yours.
The comment about backing into something and bending the shaft may be my solution since there was evidence of damage in the area.  We’ll see.

[jbcollier]

Drain the oil and fill it up with an oil with a strong colour like Royal Purple.  Then you will be able to tell where it is leaking from.

[Bread Van 74092397P]

Behind the end cover, of the 365 transmission, there is a spacer plate, with a gasket either side of it. This was the cause, of an irritating oil leak, from the rear of my Europa. It was resolved by the Lotus service garage, at the time, who advised me that the wrong gasket had been fitted. Take a look at this link for detailed illustration: http://lotus-europa.com/manuals/tcparts/f/fe.htm

May not be the problem with your car, but worth considering.

Dave

[rjbaren]

I have decided to start with the easiest approach.  I normally park in neutral, but I have decided to try parking in 1st gear, and I placed a new piece of cardboard under the trans to see if the leak slows down (or stops).  Thank you all for suggestions I will try them more or less one at a time.

This leads me to think maybe there is a chance this will work.  I had my car in storage they asked if they could put my car in their small showroom for the winter, and of course I said yes, and they never mentioned to me that the trans leaked.  Just maybe they parked the car in gear and the bent rod was in a different spot.  I will keep my fingers crossed. 

[rjbaren]

I have figured that the speedo cable is where the leak is coming from.  Can I replace the seal or do I have to buy a new cable to get a new seal?

[FourLoti]

No. The cable end pulls out of the plastic "guide" (# 32 in the diagram below)  However, you first need to remove a small bolt that acts as a locking pin for both the cable end and the guide. It's inserted through the rear of the trans mounting plate - see photo. Took me a while to figure out why I couldn't pull out the cable, but once removed, everything else can be removed. Then it's a matter of fitting new O-ring and inner seal. Hopefully, your plastic guide won't be deformed around the o-ring lip. Mine was, and I read somewhere this often happens since that gear area is the first to be exposed to heat as the fluid level drops.

Note, that locking screw is normally a hex head metric (4mm?) bolt with a thin jam nut added. The idea is to screw it in just until it engages the holes in the sides of the guide and cable end and then tighten the jam nut. My original bolt was damaged and I happened to have that phillips head screw on hand.  Actually easier to insert and lock than a hex head, FWIW.  Good luck!.

https://rdent.com/manuals/europa/tcparts/transmission/fl.htm

[jbcollier]

Pretty sure the locking bolt is 6mm x 1.0.  Lightly snug, do not tighten it down hard!

[jbcollier]

A little Permatex/Hylomar sealer won’t go amiss on the outer o-ring.

[rjbaren]

I called RD Enterprises, and the seal and "O" ring are available.  I also looked at my trans mount bolts and speedometer cable locking bolt and I find the locking bolt is in the trans in front of the trans support bracket rather than through the hole.  So, I figure I have to put a jack under the trans or block the trans and jack up the frame to expose the bolt head.  Anybody been down this road and can give some advice on which course of action is best?