Author Topic: Trans. gear Question (Read 4335 times)

dieselherb1 · « **on:** March 06, 2009, 04:07:26 pm »

Will the 5th gear from a TDI(ctn) trans. work in a 020 trans(9A)?

jtanguay · « **Reply #1 on:** March 06, 2009, 05:50:02 pm »

Quote from: "dieselherb1"

Will the 5th gear from a TDI(ctn) trans. work in a 020 trans(9A)?

apparently the 02A and 020 5th gears are different, but i always thought that they were similar, if not the same. CTN's have a 0.755 5th anyway, but 7A, FN, FF (>=7/80), and FO trannies will have the 0.71 5th which is an even better upgrade. why would you want to cannibalize a CTN, unless its junk? with some work i bet you could easily get it fit in your application.

i'm currently considering the idea of using my cable clutch to actuate a master cylinder for my CTN transmission :lol: at least it will only have cost me a master cylinder, and some bracketry to hold it all together. then i have to swap the flanges. you can even swap over the whole shift assembly from the transmission, and insert the rod shift from your old transmission to further simplify the conversion, but i have an extra cable shift assembly here (and it is superior but $$$) so i'm going to install that.

dieselherb1 · « **Reply #2 on:** March 06, 2009, 06:17:32 pm »

Did you buy those euro mounts for the ctn? Costly! I have a 02A trans with 2nd gear syncros gone. Haven't had the money or the desire to replace them, another trans was cheaper.

jtanguay · « **Reply #3 on:** March 06, 2009, 11:05:22 pm »

Quote from: "dieselherb1"

Did you buy those euro mounts for the ctn? Costly! I have a 02A trans with 2nd gear syncros gone. Haven't had the money or the desire to replace them, another trans was cheaper.

shouldn't need a euro mount for the CTN. they're just for the 6 speed boxes, or for a 4motion/synchro setup AFAIK.

btw what trans did you replace the CTN with? if you drive it right, you don't even need the synchro :wink: i would be willing to put up with the extra work for that nice tall gearing

burn_your_money · « **Reply #4 on:** March 07, 2009, 06:29:54 am »

I wouldn't put a 0.75 or 0.71 into a 9A gearbox. The gap between 4 and 5 would be huge.

jtanguay · « **Reply #5 on:** March 07, 2009, 08:12:27 am »

Quote from: "burn_your_money"

I wouldn't put a 0.75 or 0.71 into a 9A gearbox. The gap between 4 and 5 would be huge.

guess i missed the 9A in brackets :lol:

the 9A is actually an ok candidate for a taller 5th, being it has a slightly taller R&P. the transmission would work good in a turbo diesel. shift at around 3k rpm, and the torque should be able to carry the car. its around 200 rpm lower than most turbodiesel tranny's, but as stated the gearing will give a slight challenge.

dieselherb1 · « **Reply #6 on:** March 07, 2009, 04:59:17 pm »

I'm comparing gear ratios from scirocco.org. First I'm planning to put the 9A with .71 5th in a caddy with a TDI engine with IC. The CTN trans. has a r&p ratio of 3.15 the 9A has a 3.67. If you look at the span between 3-4th in alot of the diesel trans. its more than the span between 4th-5th in my 9A. I'm looking to use 5th as a overdrive. I would think the TDI could handle the 3.67-.71, it has no problems with 3.15-.75.