Richmond OD

[CJ428CJ]

Do I invest more time, energy, and money in the RG trans or give up on it and go with something else

You don't really have any other options do you unless you want to change the rear end gear ratio. Presumably you have 2.88 or maybe 3.07 gears. If you go with a Tremec 600 you might be able to get away with 3.07 gears but I think 3.31 or even 3.54 gears are much preferred.

[C5GTO]

Originally Posted by CJ428CJ

You don't really have any other options do you unless you want to change the rear end gear ratio. Presumably you have 2.88 or maybe 3.07 gears. If you go with a Tremec 600 you might be able to get away with 3.07 gears but I think 3.31 or even 3.54 gears are much preferred.

Now that you mention rear end gear ratio, my Cobra has 3.50 gears in it already. While the combination of RG with 1:1 5th and 3.50 rear gears is not ideal for highway driving, it works great around town which is about 95% of what my Cobra gets used for these days. So replacing the RG with an OD trans makes even more sense to bring the highway RPMs down and resolve all the RG trans issues I have and surely will have with continued use.

All things being equal, buying a new OD trans (most likely a Tremec) and swapping out the RG makes the most sense. But I'm 95% done with a replica Ferrari 250 GTO that I intend to start using as my around town driver. So my incentive for big ticket upgrades on the Cobra is low. I guess having both these cars is a good problem to have but it's hard not wanting to have all my cars to be perfectly optimized and have no issues.

I sent you a PM with contact info since we live near one another. Would be great to meet another Cobra guy in the Tri Valley area.

[MAStuart]

Joel I don't think trans is locked in 2 gears at the same time. As soon as you would get it in 2 gears the tires would lock up or it would strip the gears out of the trans. This would happen even with the clutch pushed in. When this happens does your tires slide?
Something is going on but I am not sure of what.

[Jac Mac]

Originally Posted by MAStuart

Joel I don't think trans is locked in 2 gears at the same time. As soon as you would get it in 2 gears the tires would lock up or it would strip the gears out of the trans. This would happen even with the clutch pushed in. When this happens does your tires slide?
Something is going on but I am not sure of what.

Exactly. If it ever selects / engages two gears at once something will have to give . One possible cause is failure of the weld on the individual shifter shaft/arm where it pass's thru the side of the case, I struck this once, it causes/allows the interlock to be 'out of phase' and leaves the trans in the previous gear when you shift up or down.

[Gaz64]

Originally Posted by MAStuart

Joel I don't think trans is locked in 2 gears at the same time. As soon as you would get it in 2 gears the tires would lock up or it would strip the gears out of the trans. This would happen even with the clutch pushed in. When this happens does your tires slide?
Something is going on but I am not sure of what.

Generally, any manual transmission would be trash if two gears were selected at the same time. While one gear stays selected, it would take effort to select the other gear.

Clearly, it cannot be gears that share the same hub, like 1/2 or 3/4 in this case.

Gary

[C5GTO]

Originally Posted by Gaz64

Generally, any manual transmission would be trash if two gears were selected at the same time. While one gear stays selected, it would take effort to select the other gear.

Clearly, it cannot be gears that share the same hub, like 1/2 or 3/4 in this case.

Gary

Great points guys. I don't know exactly what it is when the trans gets into this state. It happened to me again yesterday when I had the Cobra out for a drive around town. I happens for 2nd to 3rd shift only.

Here's what I do know. When shifting from 2nd to 3rd (issue happens when RPMs over 3,500 almost never below that), the shifter handle feels like it seizes up in mid-motion and won't let you select any gear but reverse which doesn't engage but gives a big grind noise. If I let the clutch out when trans is in this state, the rear tires squeal like they are locked up. I don't know if the drive train is really locked up or if the trans is really just still in 2nd gear. I have always kept the clutch depressed because I don't want to break something and the only fix I've found for the issue is to shift into reverse. The shift into reverse can only happen when the car is at a full stop. Once at a full stop and shifted into reverse, the trans is now cleared of the state and can be shifted normally into any other gear.

I guess the next time the issue happens, I can let the clutch out once the car slows down some and determine if in 2nd gear or not. If the trans is really in 2nd gear and shifter is not in 2nd gear position, that would tell me it's a really a shifter issue and not a trans issue. Oh well, doing more diagnosis gives me an excuse for more spirited driving! "Really officer, that wasn't an exhibition of speed, I was just trying to diagnose an issue with the transmission."

[Anthony]

Originally Posted by C5GTO

Great points guys. I don't know exactly what it is when the trans gets into this state. It happened to me again yesterday when I had the Cobra out for a drive around town. I happens for 2nd to 3rd shift only.

Here's what I do know. When shifting from 2nd to 3rd (issue happens when RPMs over 3,500 almost never below that), the shifter handle feels like it seizes up in mid-motion and won't let you select any gear but reverse which doesn't engage but gives a big grind noise. If I let the clutch out when trans is in this state, the rear tires squeal like they are locked up. I don't know if the drive train is really locked up or if the trans is really just still in 2nd gear. I have always kept the clutch depressed because I don't want to break something and the only fix I've found for the issue is to shift into reverse. The shift into reverse can only happen when the car is at a full stop. Once at a full stop and shifted into reverse, the trans is now cleared of the state and can be shifted normally into any other gear.

I guess the next time the issue happens, I can let the clutch out once the car slows down some and determine if in 2nd gear or not. If the trans is really in 2nd gear and shifter is not in 2nd gear position, that would tell me it's a really a shifter issue and not a trans issue. Oh well, doing more diagnosis gives me an excuse for more spirited driving! "Really officer, that wasn't an exhibition of speed, I was just trying to diagnose an issue with the transmission."

Maybe the brass synchro's are seizing up on the "cone" part of the gears, blocking the slider sleeve from fully engaging the selected gear. Maybe try a different lubricant ? Synthetic gear lube ?

[C5GTO]

Originally Posted by Anthony

Maybe the brass synchro's are seizing up on the "cone" part of the gears, blocking the slider sleeve from fully engaging the selected gear. Maybe try a different lubricant ? Synthetic gear lube ?

Thanks for the suggestion. I really don't think it's a failed syncro issue as the trans shifts just fine between 2nd to 3rd gear all the rest of the time. I do have a quality, synthetic gear lube in the trans. I tried to reproduce the issue yesterday with some "spirited driving". No luck, like most intermittent issues, it doesn't manifest itself when you want it to. Oh well, more spirited driving another day.