SMG swapped trans with tight shifting

[Dre1485]

My 46M had its original smg swapped for over a year (bell housing was machined). I’ve noticed one difference when comparing it to an original 6-speed car: entry into, and out of, first/second gear is much tighter in my car. Especially when the transmission is cold, this can require double clutching and abnormal effort to move.

My car has an rtd shifter, but after talking to them about my situation I realized it’s the transmission. I’ve just found out my buddy with an smg swapped 46M, and OEM shifter, is having a similar experience.

Has any other SMG conversions had a similar issue? More importantly, does anyone know a reason or solution?

[Mr.wReckless]

Did my manual swap w/o machining the bell housing like you last year. Also used an RTD shifter. Didn't really suffer from what you experience, though the 1 downside to the RTD shifter are the lack of gate adjustments, hence why I swapped to a CAE later last year. It's easier to find the 1st/2nd gate in particular as IMO it was easy to overshoot the sideways movement going into 2nd especially from 3rd.

Are you properly aligned? What is the status of the gearbox oil? Both the RTD and CAE and what I've seen from other self-centering shifters are the lack of bushings so you get more driveline noise into the shifter and cabin. I've also had a few thicker gearbox oils in mine but yet to experience a better oil than the OEM equivalent 75w80. I also have to double clutch when mine is cold to avoid grinding gears, but have found that just a slight lift of the rpms, which I imagine is to just get the synchros spin in the "correct" direction for a smoother gear engagement. This is natural when downshifting, but is a bit counter intuitive when accelerating up through the gears. But I'm not talking a massive 2000rpm blip, just a tiny rpm lift, say 50/100 rpms just to get the synchros spinning the right way.

I can also feel that it's easier to shift into gears when stationary with the engine off, how does that work for you? Other than the typical 420g gearbox stiff/poor shifting I've not really come across anything abnormal in my car after the swap. When warm the gears engage quite nicely and the CAE is nice to use.

Regards

[sapote]

1. My 46M had its original smg swapped for over a year (bell housing was machined).
2. My car has an rtd shifter, but after talking to them about my situation I realized it’s the transmission. I’ve just found out my buddy with an smg swapped 46M, and OEM shifter, is having a similar experience.

I'm not so clear here: Is the RTD shifter kind that has its own gear gates instead of the gate detent pins in the bellhousing? Then why you said the bellhousing was machined, for what?

[sapote]

OP, 1st and 2nd are in the same gate plane, do you have any issue shifting 2nd?
Re to 1st gear difficulty, does double clutching help?

If only 1st gear issue, then I don't think the 1/2 gate is the cause, but I think the clutch is not fully disengaged. check this with engine at idling in first gear with both rear wheel off ground, step on the clutch and see if the wheels still rotate. They should not with some drag force by a hand.

[Dre1485]

OP, 1st and 2nd are in the same gate plane, do you have any issue shifting 2nd?
Re to 1st gear difficulty, does double clutching help?

If only 1st gear issue, then I don't think the 1/2 gate is the cause, but I think the clutch is not fully disengaged. check this with engine at idling in first gear with both rear wheel off ground, step on the clutch and see if the wheels still rotate. They should not with some drag force by a hand.

It is first and second; i tend go from first to third and forgot to include in the post. Good clarification. Double clutching does help moving into the gate, but not with the tightness moving out the gear.

[Dre1485]

I'm not so clear here: Is the RTD shifter kind that has its own gear gates instead of the gate detent pins in the bellhousing? Then why you said the bellhousing was machined, for what?

Chassis mounted shifters don’t have their own gear gates. It makes finding the gear much harder. CAE does offer and adjustment directly on the shifter to help, but I realized I wanted the OEM detents.

[Dre1485]

Did my manual swap w/o machining the bell housing like you last year. Also used an RTD shifter. Didn't really suffer from what you experience, though the 1 downside to the RTD shifter are the lack of gate adjustments, hence why I swapped to a CAE later last year. It's easier to find the 1st/2nd gate in particular as IMO it was easy to overshoot the sideways movement going into 2nd especially from 3rd.

Are you properly aligned? What is the status of the gearbox oil? Both the RTD and CAE and what I've seen from other self-centering shifters are the lack of bushings so you get more driveline noise into the shifter and cabin. I've also had a few thicker gearbox oils in mine but yet to experience a better oil than the OEM equivalent 75w80. I also have to double clutch when mine is cold to avoid grinding gears, but have found that just a slight lift of the rpms, which I imagine is to just get the synchros spin in the "correct" direction for a smoother gear engagement. This is natural when downshifting, but is a bit counter intuitive when accelerating up through the gears. But I'm not talking a massive 2000rpm blip, just a tiny rpm lift, say 50/100 rpms just to get the synchros spinning the right way.

I can also feel that it's easier to shift into gears when stationary with the engine off, how does that work for you? Other than the typical 420g gearbox stiff/poor shifting I've not really come across anything abnormal in my car after the swap. When warm the gears engage quite nicely and the CAE is nice to use.

Regards

I did center the RTD shifter. I was originally using fresh redline fluid after the swap. I later switched to OEM, which I feel did help. Double clutching and rev matching does help when the trans is cold. I’m not sure the CAE gate adjustment would help. Pulling the shifter out of 1st/2nd gear is the main issue I’m trying to solve for. Sometimes it takes a lot of force and sounds like a louder rear diff clunk coming from the transmission.

[sapote]

1. Chassis mounted shifters don’t have their own gear gates. It makes finding the gear much harder. CAE does offer and adjustment directly on the shifter to help, but I realized I wanted the OEM detents.
2. It is first and second; i tend go from first to third and forgot to include in the post. Good clarification. Double clutching does help moving into the gate, but not with the tightness moving out the gear.

1. So does the bellhousing have the modification to have the detent pins added? Sorry I am still confused after your answer.
2. This means the 1/2 gate detent components were not set properly. Since I still not clear if the gates are in the shifter or in the bellhousing, I have suggestion on this.