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MG TD TF 1500 - Crunchy gearbox

I recently acquired a '53 TD. When I shift through the gears gently at low RPM all is well, but if I try to accelerate with any gusto, or raise RPM above a certain level before shifting, I grind gears going up or down. Also a knocking noise is present on harder acceleration which I can suppress by pushing and holding the gearshift forwards into gear. What might the problem(s) be? Thanks, Jonathan.
J H Bullen

Would that knocking be in first gear only>
Sanders

If your transmission grinds I would first check the level of transmission oil, to sure you are fully topped up. The owner's handbook will give instructions. Low oil will cause grinding and difficulty in shifting.

I would also check to see that the clutch linkage is properly adjusted, and consider making the O'Connor modification (see http://www.ttalk.info/ClutchLinkageFix.pdf). The clevis pins and clevises wear out-of-round, sometimes causing so much free play that making adjustments is difficult.

Of course, it is also possible that you are rushing the shifts, perhaps being accustomed to a more modern gearbox. One must pause momentarily in neutral between gears to permit the synchros to catch up, and then shift deftly to the next gear.

Tom Lange
MGT Repair

t lange

"I would also check to see that the clutch linkage is properly adjusted, and consider making the O'Connor modification"

The 53 TD doesn't need the O'connor modification. The 53 had the clutch stop bolt from the factory and unless someone maladjusted the stop bolt, It will be in the correct position. Contact me at SUfuelpumps@donobi.net and I'll send you the information on the Clutch pedal stop bolt.
Cheers - Dave
DW DuBois

The synchro a could be shot. Regards, tom
tm peterson

Of course, you are right, Dave. I forgot. For some reason I seldom get 53's in to work on. I wonder why?

Tom Lange
t lange

In the year & a half that I drove mine I couldn't get it into second or third gear without crunching so I quickly learned to double de-clutch going up & going down & never again had any problems. When I stripped the box to rebuild it I fully expected to see very worn synchros but they looked almost brand new & the teeth on the gears were in great shape. Double de-clutching does work & certainly protects the gears. I also remember really liking the sound it makes. And it used to make the old timers that I passed smile. Cheers
Peter TD 5801
P Hehir

What oil is in the box?

Matthew.
M Magilton

You might get lucky. I did. Change the gear box oil to RED LINE MT-90.
Peter Dahlquist

Instead of pausing in neutral, I would recommend to just push slightly the stick toward the gear position. Waiting for synchros to operate. You can hear it. You can even feel it with a little experience. Take your time. And then, push the stick into gear.

I've got another car with poor synchros and it was very well as is.

Laurent.
LC Laurent31

Dave D,

The O'Connor mod not only helps with crunchy gears, it also helps with grabby clutches as was the case with my 53.

Jim
James Neel

Thanks for all the input. I checked the box for oil, and it's full. I don't know what brand of oil is in it. The knocking sound is audible in second and third gears, but not first or fourth. I have tried the double declutching and careful pause in neutral to no avail. Maybe my technique isn't up to snuff! I'll check clutch adjustment next.
J H Bullen

Re Red Line oil, the expert who rebuilt my differential says that his warranty is void if any other oil is used in it.

David
D A Provan

+1 Redline, Notable improvement.

Matthew.
M Magilton

I just replaced the MT-90 in my diff with standard GL-4 80-90. If you look on Redlines' web site, MT-90 is not recommended for diffs. I don't know why that is, but in the ~100 miles driving with it, the differential whine was noticeable, esp. on steep hills.

Great in the tranny, though.
MC Logan

Does anyone have a notion what might be causing the knocking noise in second and third? I'm able to suppress it by pushing hard on the gear shift lever, but it is, to say the least, a bit troubling.
J H Bullen

Bad bearings, worn gears, too much ignition advance, weak anti-rattle spring. Any of these have been known to cause knocking.
Lew Palmer

Redline MT90 absolutely changed my gearbox - highly recommended. Gear changes are easier to make; smoother operation and definitely quieter.

Gord Clark
Rockburn, Qué
Gord Clark

This thread was discussed between 04/08/2017 and 15/08/2017

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