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First gear "crunch"

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I've lived with it for over 2 years on my MGB. But mine is only on downshifts while moving. 2nd gear used to be bad on mine too, but has lossened up alot in the 2+ years of me driving it.
 
Taint supposed to do that, Larry. It's your call but I would speak to the guy that did the rebuild. Now, that said, I suspect that this person did the rebuild some time ago, knowing that your restoration was over a long time. Most shops will give only a 12 month warantee, max. You may be out of luck. All you can do is baby it in this situation, it hopefully won't get worse, meaning losing your synchro.
Er, no chance you have high detergent oil in that tranny. I would recommend straight 30 wt Non detergent oil (Valvoline), especially with your overdrive.
Bill
 
For the last 87,000 miles I have used nothing but Valvoline 20W50 Racing oil in my TR3A gearbox and overdrive. Early in the recent history of synthetic oils, many complained about the synthetic oil being too slippery and it would pop out of gear because the syncros need a bit of friction to work. If you are using a synthetic oil in your gearbox and overdrive, switch back to a normal oil such as the Valvoline 20W50 Racing and see what happens.

But also try to go into first gear from 2nd gear. With the gearstick in 2nd gear, depress the clutch and flip the gearstick from the gate for 2nd gear into the gate for 1st gear. This will help synchronise things and may eliminate the "crunch". We owners of TR3As don't have synchro in 1st gear so this helps, even if we are stopped in neutral at a red light and the light goes green.

Don Elliott, Original Owner

https://www.zen21606.zen.co.uk/Forum%20Gallery/don3a2_big.jpg
 
Larry, I think unfortunately you might have gotten an aftermarket replacement synchro ring that was not quite up to the job. I have seen a number of replacements over the last ten years that really appeared suspect. The file like ridges on critical cone clutch surface didn't stand nearly as pround compared to a NOS leyland unit. Which also means that you're likely to have problems with 2nd and 3rd later on. Good luck.

Tom Lains
TS8651
TS58107
 
Continue to observe the situation. If it continues to worsen, you could have a hydraulics problem.
Where did your components come from and what fluid are you using?
My clutch master from vb was toast after 9 months(5 months of driving) using silicone. Silicone has been excellent with components elsewhere.
 
Adding to Don's comments about the lubricant. The TR gearbox requires GL4 gear oil. Redline MT90 is one of the few GL4 oils out there. It is synthetic, but is not supposed to be to slippery. One of my next service items is to drain and refill my tranny with MT90. I'll also be doing our Miata.
Years ago my brother had a Healey 3000. As best I can recall first gear was non syncro. The proper method for downshifting into first was to do so when the car was almost stopped. It would slide into gear with no grind or crunch. Based on Larry's description my guess is either a weak syncro, or the wrong oil. Possibly GL5 since it is far more common.
 
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