T56 snatchy notchy crap when driving gently.
03-01-2011, 04:23 PM
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T56 snatchy notchy crap when driving gently. When I drive hard, or even just a little hard, my T56 slips into gears wonderfully. In fact you can't even feel anything mechanical happening.
But when driving gently, and dropping into the next gear just as the engine RPM naturally drops to about the right point, i.e. gentle cruising, it's horrible. It's notchy, snatchy, grabby, wobbly. ****.
Aaaaarrrrgh. What can I do ? I'm wound up even just thinking about it
I've tried expensive oils.
I rebuilt the box with new synchro blockers and keys not long ago. That fixed the hideous grind that I had when going into second gear. Many of the engagement dog teeth were worn, and synchro slider teeth. I re-pointed them with a dremel.
The more I search, the more I start to think that this is just how this box is.
My shifter is a direct piece - no rubber isolation like OEM has. That won't help
Can anybody explain what is actually going on inside the box?
There does seem to be a lot of "slack" in the drivetrain as a whole. I'm not sure if that's my LSD. Could excessive play in the differential cause weird shifts? I'm not sure I can see how it could, but thought I should add that anyway
But when driving gently, and dropping into the next gear just as the engine RPM naturally drops to about the right point, i.e. gentle cruising, it's horrible. It's notchy, snatchy, grabby, wobbly. ****.
Aaaaarrrrgh. What can I do ? I'm wound up even just thinking about it
I've tried expensive oils.
I rebuilt the box with new synchro blockers and keys not long ago. That fixed the hideous grind that I had when going into second gear. Many of the engagement dog teeth were worn, and synchro slider teeth. I re-pointed them with a dremel.
The more I search, the more I start to think that this is just how this box is.
My shifter is a direct piece - no rubber isolation like OEM has. That won't help
Can anybody explain what is actually going on inside the box?
There does seem to be a lot of "slack" in the drivetrain as a whole. I'm not sure if that's my LSD. Could excessive play in the differential cause weird shifts? I'm not sure I can see how it could, but thought I should add that anyway
Last edited by carl0s; 03-01-2011 at 04:31 PM.
03-01-2011, 06:03 PM
#2
does it feel kind of like the dogteeth are clashing on each shift? like for a fraction of a second it almost feels like it's going to grind or pop back out (can't hear it, just feel it for a hair of a second) as it slides into gear?
I have about 5k miles on my rebuild (basically EVERYTHING replaced) and noticed when I'm really on it it's nice and smooth, but when going easy I feel something going on in there through my shifter. I have a factory hurst with the short stick and an aluminum ****.
I have about 5k miles on my rebuild (basically EVERYTHING replaced) and noticed when I'm really on it it's nice and smooth, but when going easy I feel something going on in there through my shifter. I have a factory hurst with the short stick and an aluminum ****.
Last edited by therealcreeper; 03-01-2011 at 07:20 PM.
03-02-2011, 07:17 AM
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Yes that's *exactly* how it is. I tried filming it before. For a fraction of a second, it sort of bounces/buzzes back out...
Did you replace the gears themselves - are your dog teeth nice and new?
Did you replace the gears themselves - are your dog teeth nice and new?
03-02-2011, 08:26 AM
#4
new 1-2 synchro, 2nd gear, steel 3-4 fork, mainshaft, blocker rings, bearings, new plastic fork pads, new standard slider keys, new shims, new seals
I've also tried different fluids with no luck
I've also tried different fluids with no luck
03-03-2011, 11:50 AM
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I guess this is just how they are then I'm considering fitting an OEM GTO shifter handle/**** that has some rubber isolation bulit in. I just ordered an MGW shifter though
Lame
It just ruins the whole car. Between the 19-year old feel of the suspension/bushes, and this shitty "NVH? WTF is NVH?" gearbox, the whole car just feels a bit rough.
03-05-2011, 07:37 PM
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I noticed something the other day that I think might be related.
When moving at low speeds in 2nd gear, I can hear the gear whining. If I am off the gas, i.e. 850rpm, in second gear, and I dab the gas pedal, well as you would expect, the car lurches a bit, but what I notice is a *lot* of slop in the gearbox.
How about yours?
I was thinking about my Dremel re-pointed dog teeth. They have obviously lost some height. I am thinking about replacing gears and synchros. I only did blocker rings last time.
You say you have replaced 2nd gear and 1-2 synchro. Well, do you have this problem in second gear? Or perhaps just other gears?
When moving at low speeds in 2nd gear, I can hear the gear whining. If I am off the gas, i.e. 850rpm, in second gear, and I dab the gas pedal, well as you would expect, the car lurches a bit, but what I notice is a *lot* of slop in the gearbox.
How about yours?
I was thinking about my Dremel re-pointed dog teeth. They have obviously lost some height. I am thinking about replacing gears and synchros. I only did blocker rings last time.
You say you have replaced 2nd gear and 1-2 synchro. Well, do you have this problem in second gear? Or perhaps just other gears?
03-05-2011, 11:48 PM
#7
it's almost entirely 2nd gear, which had everything replaced. the rest is fine, unless I put it into 1st still rolling too quick then it's a similar feel. the rest of the gears go very smoothly.
all downshifts are smooth as butter also, it's really just the 1-2 shift that does it
I have slop in the drivetrain also, but I think it's mostly U-joints and my 10 bolt
all downshifts are smooth as butter also, it's really just the 1-2 shift that does it
I have slop in the drivetrain also, but I think it's mostly U-joints and my 10 bolt
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03-29-2011, 05:49 PM
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As I mentioned at the bottom of my first post, and as we have discussed via PM (but for the benefit of others that might be reading), I had been wondering if excessive differential play/backlash could be a cause - perhaps by loading/unloading the output of the transmission. This could be compounded by me having a single-piece propshaft with no rubber coupling (car is a '92 RX7 FD with an LS2 swap from a GTO).
I will see what my replacement LSD does, and explore the possibility of a two-piece propshaft with some sort of shock absorber/compliance/guibo in the middle of it.
03-29-2011, 06:34 PM
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My clutch is fine. I have done so much with the clutch anyway. It doesn't drag, it is adjusted loads, and is (was, recently) a new LS7 type, with new slave, and new Tilton 7/8ths master cylinder, and a slave cylinder shim just in case ..
