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MG MGB Technical - Still hard to get into reverse

Hi All,

I posted a while back about having a hard time getting my '79 MGB into reverse. It goes into gear OK, but it's really difficult to get it over past the 1st - 2nd gear position into line with the reverse gear. The advice I got was that they are kinda hard to get into reverse anyway & I should just give it a whack & it'll go in. Well, sometimes that works, but most of the time it doesn't. I can always get it in by pulling the shifter toward me & working it back & forth a bit and it'll eventually go over, but my wife isn't strong enough to do it. Now, she is the one who wanted a convertible in the first place (don't know how I talked her into a B), so I'm getting a bit of heat over the fact that she can't drive the thing. Is there a simple adjustment I can make or should I just take it to a tranny shop & tell them to fix it?

Thanks for the help,
Rodney
Rodney Isom

Rodney: There is no "simple adjustment" available. The gear selector rod travels in an extension on top of the gearbox that is partialy exposed at the rear. You could check to see that it is all clean (you'll need a lift or put it on four jack stands). The gear lever fits into the selector and by moving the lever you rotate and/or slide the selector in and out, that, through other rods and forks in the box, move gears sets into and out of engagement. If there are not any problems in the extension then the problem is internal. There is a reverse detent ball and spring that is really only accessible by dismantling the gearbox.
I would consider finding a good used gearbox ( there are plenty around) before I would take it to a non-mg specialist transmission shop for a rebuild by someome with no MG experience.
Cheers, Andy
Andrew Blackley

If a transmission has been abused by some hamfisted and angry PO, it is possible that the shift forks may have gotten bent. I admit that I forget if these affect the shifting into reverse, but if so, I suppose that might be something to check out. I have seen bronze forks bent up pretty badly and all we could figure was that someone had slammed the shift lever around pretty hard.

There is also some sort of lock out toggle (fig. 91 late gearbox, Moss Cat. Pg 104) and if that little widget is out of whack with the rest of the linkage, I think it might be a reason for shifting problems. I will be interested to see what more learned minds have to share on this topic.
Bob Muenchausen

I have the same problem on mine where it doesn't want to go into reverse at all. When this happens, I put it into 1st, pull forward slightly then try again. Usually, it will slide right into reverse with no problem. This almost always works. Don't ask me why. It's been that way for 17 years now....

Robert

Robert Rushing

'lo all.

There's a big detented spring in the extension piece of the gearbox that stops the lever moving over. The spring is held in by a bolt type thing so I guess you could take the bolt out and change the spring. There's still the detent to get past of course which is held in by another bolt/spring that you may like to inspect.

Given the size of the hole in the top of the later tunnel, I would doubt that you could get to these while the trans is in the car...

Once you get it past the detent, is it free to move? There's the spring obviously but I mean is it binding at all?

ttfn,
--
Olly
Oliver Stephenson

Before you do anything expensive, examine the clevis pins at the clutch pedal linkage and at the slave fork. If these are worn (only a 1/32" or so), shifting will be difficult since the clutch isn't 100% released. Together, these pins only cost about $3, so it's a cheap and easy step to take.
Dan

Once I get it over past the detent, it goes into reverse easily (ok, sometimes I have to do the pulling forward trick but usually not), but the hard part is getting past the detent.

Is there anywhere I can get a detailed diagram of the location of the innards of my transmission? I'd like to be able to see exactly where some of the parts mentioned here are located.

Thanks,
Rodney
Rodney Isom

Rodney...

A close look at the diagrams in the Moss catalogue should show you where everything is. The bits you are interested in are to the right of the opening on the top of the extension piece (the bit that the shift linkage bolts on to).

Hope this helps,
--
Olly
Oliver Stephenson

I have a similar problem with my 78B. It worked fine until several months ago. If I depress the clutch and try to put it in reverse it goes into 2nd. If I let the clutch out and press left and down with the lever it grinds a little and then I can put it in reverse. I bled the slave cylinder, but it didn't help.
Mark Neisser

Rodney - Your problem sounds like on that I had with and early, 3 syncro transmission. The detent assembly was worn to the point that I could either adjust it to where I had to fight it to get into reverse or so loose that I had to be extremely careful when going into second or I would catch reverse (terible noises when that happened. The same problem could manifest itself with the detent that operates the reverse light switch. I am sorry, but I don't know where to tell you to look on the 4 syncro boxes, but I would bet that your problem is one of those two places.

Mark - your problem sounds like what Dan in San Francisco talks about. Check out the clevis pin holes in the pedal to master cylinder attachment point also. You might also have a bad master or slave cylinder.
Good luck - Dave
David DuBois

This thread was discussed between 02/06/2002 and 03/06/2002

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