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downshifting problems

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19_again

19_again

Jedi Warrior
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Well I finally got the new B on the road today!!! The new Peco exhaust is louder than I expected, but perhaps it'll quiet down as the gaskets and the muffler break in? But I can't downshift into second, it goes through all the gears fine, has 70 lbs oil pressure and no leaks anywhere so I'm very encouraged. Only 69K miles on the '66, need lots of little stuff and brakes are quite hard. When I try to downshift into 2nd, I get a great grinding effect. I've tried double clutching and that seemed to work, but given that today was the bmaiden voyage after a carb rebuild as well as the new Peco, I wanted to tahe it easy. Any ideas on the downshifting issue? Down into 3rd is fine.
Mike
 
sounds like the 2nd gear synchro is giving up. Good used B trannys are dirt cheap so it's hardly worth rebuilding.
 
Second gear balk ring is the one to go in most B gearboxes... for that reason I'd rebuild. By all means have another box to-hand if possible, but go thru it before you do the swap. It'll be "labour savings" in the end... and that is a non-syncro first gear tranny... DO NOT under any circumstances attempt to engage first or reverse unless the wheels are dead stopped! You'll have a right proper mess otherwise.

Mebbe you knew this, but I feel obligated to post it, anyhow. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
The second gear baulk ring (syncro)is considerably smaller than third and fourth baulk ring and consequently wears out before the others. The factory knew this of this problem for over ten years and corrected it a few months before the 3-syncro gearbox was replaced with the all-syncro gearbox. The brass baulk ring is replaced with a steel ring along with the second gear. You must replace the gear and ring together as the new gear has a coating on the cone same as waffle boxes. Part #'s 22H249/22H230. I am building two gearboxes this week with the updates. One is an MGA and the other is an MGB D-Type overdrive which is also getting the four bearing laygear update which came along about the same time as the second gear update.
I am sure that many on the forum will suggest that you install a full syncro gearbox in place of the one you have now. That would be the cheaper way out. As delicate as they are comparatively , I still prefer the earlier gearbox because of the much better ratios.

So There...

Alan T
 
doesnt he need the wider tranny tunnel to install the 4 synchro box?
 
My first impulse is to say "yes. The early tunnel is too narrow".

As for AlanT's preference for the earlier "crashbox" I agree totally. Hvae two here, and consider 'em "in rotation". Four bearing layshaft is a good improvement. Can usually get 80~90K out of a box before it needs "rotating", too. /bcforum/images/%%GRAEMLIN_URL%%/laugh.gif
 
No, I have fitted a late model 4 syc. overdrive gearbox to my 63 B with out any mods to the tunnel. I love it, cuz you can delete the extra wiring and vacuum switch.
Cheers, David.
 
The four-syncro box is a tight fit in the earlier car. I have seen some cars that had the starter area whacked for more clearance but I do not believe it was entirely necessary. You do have to modify the tunnel on the top side. The later gearbox has a longer shift tower. Now if you want to install an early gearbox in a later car you simply flip the tunnel cover 180 degrees.

Alan T
 
I do have also the late model 4 sync.

I just removed the old oil and it doesn't look like the 20w/50. I think it's more like the EP90? Should I stick with the specified 20w/50? Is there any additive I should add to it to last longer? What do you think about the redline oil?

Don
 
That is exactly what I did, Alan. If I remember correctly, it needs to move toward the rear of the car about 1 1/2" to 2". No need to mod the body tub.
Don, your unit should be filled with motor oil. Using gear oil makes for hard shifts, and non operational overdrives on cold days...just to name a few problems.
Cheers, David.
 
My vote is for the original box and the improved 2nd gear & synchro Moss #461-495 ($78.95) & #461-480 ($43.95)

Also while you're in there replace your lay shaft & bearings.
(not all cluster gears are milled far enough in for the quad bearing setup so inspect it)

The 1st motion shaft bearing is also another good one to check.
(anything more than 1/2" wobble and I'd do it)

And replace front & rear seal.

Try Red Line MTF for lube!
(I love the stuff and it's not too slippy)
 
461-480 is not in stock at the moment and none on the way according to my sales weasel at Moss. I may have bought the last 461-495 also.

Alan T
 
Step right up.....Time to play find that part.

Our first contestant is from New Hampshire & can't find 2nd....

Let's all welcome 19 Again....*Applause*

Your challenge is to find a steel synchro & gear without going insane or broke.

Now lets meet your adversaries.....

Bert runs a breaker's yard but is too lazy to check to see if he has the part and would rather be watching reruns of Charlie's angels and munching on fast food.

Carl knows he has about 10 and is waiting for the price to go up.

Ernie has a new one installed and one extra but will hoard this until you pull it out of his cold dead fingers.
(Even though the car almost never leaves the garage)

And the big parts giant is dragging its feet while they look for the lowest bidder, have committee meetings & conduct consumer studies.

[Try here.... https://www.quantumechanics.com/categories.php?op=newindex&catid=3]

(Or you can use a bronze one and try not to shift like you're 19 again /bcforum/images/%%GRAEMLIN_URL%%/grin.gif )
 
I've a "kit" goin' into the spare. Got it a few years ago. Bronze ring, no big deal... I double-clutch the downshifts. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
Well I am a little smarter than when I was 19, and back then my '65 B was my only car. Double clutching when downshifting is today's answer. It's too late for either insane or broke, so that saves a lot of deliberation right there. The smarter part comes into play now, because I'm smart enough now to pay someone else to do the stuff that I'd otherwise screw up twice and then pay him anyway. I can try and make it through the summer and deal with it come a snow day. Once again the forum comes through, and I'd like door #4 please.
 
Actually it's not hard to rebuild one and you'd have to screw it up more than twice in order to equal what a refurbished one will cost.

Then there is the satisfaction of having another manly accomplishment to your credit.

Women will swoon, other men will envy you and children will sing your praises.

Or you could put up shelves for your wife /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

https://mgaguru.com/mgtech/gearbox/gt203c.htm
 
My most manly accomplishment to date has been to know my limitations. I can put up 20 shelves in the time it will take a smarter person to repair my tranny. While there is indeed satisfaction in the accomplishment, (I still can't believe I even attempted to replace my exhaust system from manifold to tail pipe all by myself, I was also surprised at how easy it was) the excitement of having a tranny laid out on my garage floor would put ME into a swoon.
And shelves just do something to my wife that is inexplicable, it's a win-win!!
 
19_again said:
And shelves just do something to my wife that is inexplicable, it's a win-win!!
Click to expand...

Gee, wonder what that is. LOL
 
Fast answer is to just change the synchro ring and mind your shifting way to make it last longer than the usuall 3 days!

I much prefer the early non-synch box (I have cars with both types). Particularly the early box with close ratio gears, which is what I race in whatever MG powered beast I happen to run - really sweet box with perfect ratios.

Anyone that has the chance should convert to the 4 caged bearing laygear (used only in the last year of the early box) which is considerably stronger. I put a lot of torque through the one in my race car and so far I haven't needed to get out my close ratio gear set for the all synch box.
 
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