Popping out of second gear

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Kenmgtc
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Location: Farmington Hills, MI

Popping out of second gear

Post by Kenmgtc » Tue Jun 19, 2018 11:57 am

Hi all, I think i know the answer to this one, i just don't like it! :)

I was told when i bought my TC it would pop out of 2nd gear. Didn't do it on the test drive and didn't do it for a while til one day it started a block from home. So i replaced the balls and springs, checked all the fork bolts, filled it with new oil and it was fine again. For a while.

Today on a long drive (200 miles) it started again. At first it was ok just keeping my hand lightly on it if i de-celled. By the time i got home it would only occasionally stay in gear if i pulled back hard and even then it would sometimes pop out. Not very good for the forks/dogs to be doing that.

I assume the real problem is second gear is worn out? I do notice that the car never really snaps into 2nd like all the other gears either. The stop on that rod does go all the way to the front of the case. Anything else i should be looking for since it appears the transmission is coming out of the car?

Another thing with that transmission.... is the dipstick really only held in place by the rubber snug? what keeps dirt out of the hole? One would think the dipstick should positively insert in the transmission case; maybe mine is missing some sleeve. When i did the oil i wasn't sure so i drained it completely and refilled with the correct amount (900ml), which came up to the full mark on the dipstick.

thank you!
Ken Klemmer
1948 TC 5510

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stephen stierman
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Re: Popping out of second gear

Post by stephen stierman » Wed Jun 20, 2018 5:35 am

Mine will do the same thing in second particularly when cold on the over run, never going up through the gears. When I had the box out and apart years ago I did some shimming of the main shaft as I recall based upon an article that I had read. It really did not help. I suspected the balls and springs in the synchro hubs might be week or a shift fork might be worn, but not really sure. I can tell you that second gear is "not worn out" but there is something that one can do correct this although I am not sure what it is. Honestly second gear is so low that I am seldom in it on the over run and if I am I just rest my hand on the lever and it will stay in gear. On a good hot day after warming it is usually fine.

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Steve Simmons
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Re: Popping out of second gear

Post by Steve Simmons » Wed Jun 20, 2018 7:41 am

The dipstick should bottom out on metal and not rest on the rubber.
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
http://www.mgnuts.com

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searunner
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Re: Popping out of second gear

Post by searunner » Wed Jun 20, 2018 9:49 am

On My TD I have same problem BUT for the FIRST gear . Pop out on the climb ramps
My gearbox was recently rebuild by my self- NO others problems displayed in more than 2000Km
On previous set, this issue was NOT present, problems are the 2-3 sincro hub
I have read that problem can be the insufficient tightening torque of the(rear) Main shaft bolt -- someone can confirm???
No a real problem the car can start from stop in Second gear, also if road climb up
and my rear axle ratio is a 4.33:1

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Kenmgtc
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Location: Farmington Hills, MI

Re: Popping out of second gear

Post by Kenmgtc » Thu Jun 21, 2018 5:40 am

Steve Simmons wrote:The dipstick should bottom out on metal and not rest on the rubber.
ok, thanks for confirming!
Ken Klemmer
1948 TC 5510

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Kenmgtc
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Re: Popping out of second gear

Post by Kenmgtc » Thu Jun 21, 2018 5:45 am

Thanks to everyone who responded. I decided to take the motor and transmission out, since i am also finding moisture in the valve cover. I'm sure it will be fairly obvious what's wrong with the transmission once i can actually see in it.

I've almost finished stripping everything down and will probably hoist out the motor tomorrow. The motor has reportedly never been out of the car in at least 50 years of previous ownership, so it will be interesting what i find. Kind of scary because it runs so good, but the water issue is a big red flag.
Ken Klemmer
1948 TC 5510

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Kenmgtc
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Location: Farmington Hills, MI

Re: Popping out of second gear

Post by Kenmgtc » Mon Jun 25, 2018 3:28 am

Progress report: The engine and trans are out and the trans separated. Nothing looks terrible but I’m glad I took it apart. The rear flange nut wasn’t pinned and the nut was very loose, enough to slide the flange fore and aft. There is a little play in the front bearing, not sure if it’s bad enough to worry about. But the layshaft has about .030-.040 of end play. So definitely new thrust bearings needed there.

Question about the 1-2 sliding dog. Is the purpose of the balls and springs solely to keep the dog in the center detent or so they also impart a necessary friction to the system to help keep it in gear? Should I replace them? Probably cannot hurt.

I had just replace the shift rod springs and balls a few weeks ago so they will go back in.

Thanks
Ken Klemmer
1948 TC 5510

Bob Grunau
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Re: Popping out of second gear

Post by Bob Grunau » Tue Jun 26, 2018 11:07 am

Loose flange nut will cause the problem.
Shim in front of the rear bearing 0.040" to move everything and the gear forward.
Make sure shift forks have only about 0.004" free travel in the slot.
Cluster end float should be 0.004" to 0.006", I do have some thicker washers to install on your thrusts.
Sliding dog detent springs will have liitle effect on gear location.
Bob Grunau 905-274-4136

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