Rear oil seal et al

[foster461]

I also used my gearbox for 20 years with no lifting. When I mentioned this to the guy who rebuilt the box he laughed and said he often gets calls from people after they refit their rebuilt box to ask how to get into reverse. He claims that in all cases the original box was worn, that the spring in the lever mechanism is there to resist the accidental engagement of reverse (ie going into reverse instead of say 4th). After 20 years I'm still skeptical so I go look in the book. The first book I come across is Haynes, page 121 in my copy that shows a cross section of the gear change mechanism, sure enough the gates for 1234 are all in the same plane but reverse is raised about an eight of an inch so the stick has to be pulled up to get into the gate.

 

But heck, this is the TR6 forum, who lifts and who doesnt ??

 

Stan

[Guest ron]

Stan

I'm with Richard on this, my gearlever doesn't need lifting to get reverse, and when I rebuilt the box there was no sign of that amount of wear in the gearchange mechanism, in fact it's hard to imagine it would wear as badly as that unless the car had been to the moon and back!

As well as TR6 boxes I've also stripped a very low mileage Dolomite Sprint box which is the same as the late TR6 box apart from the input shaft and it didn't have it either so my guess is that maybe the very early cars had it and they dropped it for later models or it's bad manufacturing tolerances which even for Triumph seems a bit unlikely.

Ron

[foster461]

Well, all the books show there is a step in the gate going into reverse. So if we dont lift, what is it that gets us over this step ?. If its not wear in the gate or the bottom of the gearstick (and I agree it would have to wear a LOT to overcome this step) what makes it work ??. Does the gate orientation change during reverse selection (doubtful) or does the gearstick pivot so that it moves in an arc and avoids the step ?. Something is missing here..

 

 

Stan

[Guest ron]

Stan

I've just had a look at another gearbox I forgot I had [as you do!!] and my last post is a load of nonsense, there is a definite step up at reverse gear of about 1/8" but the lead into it has a curved chamfer of about 45 degs. which probably accounts for the fact that after the box has been used and eased up a bit the gearstick will rise up this without actually having to lift it.

Ron

[foster461]

 

ok, my reverse gear selection is working as before. Some slight resistance going into reverse but no lifting required.

 

Here's the scoop. Once again stupidity is the main culprit.

 

If you recall this started with me adding overdrive to a non overdrive transmission. When I took the old gearbox out I noticed there was a support bracket on the right hand side. This bracket cant be used once the overdrive is added. Being the creative mechanical genius that I am, I decided instead of using the original bolts that secure the gear stick cover (and the bracket), I would use a set of adjustable bolts from a TR4 gearbox since they seemed to reflect the adjustment text in the manual and looked nicer since there was no extraneous nut left over due to the now omitted bracket.

 

Bad idea.

 

The original bolts from this TR6 are *different lengths* and are not meant to be adjusted. The long one goes in the RHS and the short one goes in the LHS. These bolts have a direct effect on the orientation of the gear stick in the gates.

 

Once I replaced my TR4 bolts with the original ones, voila, reverse works correctly.

 

Phew.

 

Stan

[Richard Crawley]

The manufacturer’s handbook states “ Reverse – Move the lever sharply to the extreme right an rearward. Engage only when the vehicle is stationary”.

 

As I said, no lifting required; in fact I tried with 2 hands to get the thing to lift & couldn’t do it.

[Tom Fremont]

As I said, no lifting required; in fact I tried with 2 hands to get the thing to lift & couldn’t do it.

Must be some bodacious spring you've got in there, Richard! :laugh:

[foster461]

One other factor.. I have noticed that if I'm sitting in the passenger seat, using my left hand to put the gearstick into reverse is easier than sitting in the drivers seat and pushing it into reverse. So right hand drive cars have an easier job I think. The action from the RH seat is a lot more natural in my opinion and it goes in much smoother than from the LHs where pushing and pulling up slightly is harder than pulling and pulling up. And that spring is pretty strong, for me to compress it I have to use both hands and give it a good heave so there is no way reverse is going in smoothly if that spring has to be compressed to any degree.

 

Stan

[jonlar]

The action from the RH seat is a lot more natural in my opinion and it goes in much smoother than from the LHs where pushing and pulling up slightly is harder than pulling and pulling up.

I think that is spot-on Stan.

[vanflyer]

Since reading the last few posts i had a go at lifting the lever ever so slightly, It does engage reverse smoother that the brute force approach. Was there a difference in the early boxes to the later ones prehaps? Mine is a 1969 LHD CC26037.

[foster461]

This design seems to go all the way back, at least as far as the TR4A based on what I have personally observed and I would bet to the previous generation too.

 

Stan