Author Topic: Which transmission?  (Read 2377 times)

September 18, 2004, 07:18:00 am

racer_x

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Which transmission?
« on: September 18, 2004, 07:18:00 am »
Does anybody actuall vote in the polls here? Or is the poll feature broken?

More questions. I have had a 4K transmission in my 1984 Jetta diesel (1.6D Normally Asthmatic). It's nice from a stop, but the revs are a little high at highway speeds. Also, my highway mileage dropped some with this transmission. I still have the old 7A for parts (diff bearings failed), and I have a few other "parts" transmissions here as well.

I picked up an FN  code transmission and I was going to put that in this weekend. I still might, but I was thinking about maybe making a hybrid transmission that might be better suited to my car and my driving.

I like the tall 5th gear from the 7A (and the FN is pretty tall as well), but I like the closer 1st through 3rd from the 4K. The 4K accelerates much better from a stop through the first three gears. I though about putting the 0.71:1 fifth gear set from my 7A into the 4K, and that would sort of solve the highway revs problem, but the gap from 4th gear (1.13:1) to 5th gear (0.71:1) would be huge. If I needed to drop to 4th on the highway for some reason, it would be pretty useless.

The last option I'm considering is putting 4th and 5th from the 7A into a 4K. That's more work because the main case has to be opened, but I could also throw a bolt kit in while I have it apart and make it pretty much bullet proof for the diesel. That would give me good acceleration from the stoplight with the close ratio 1st, 2nd and 3rd. It would give me an "economy" gear for city streets in 4th (0.91:1) which would double as a hill climbing and "passing" (yeah, right) gear for the highway. And, finally, I'd have the highway cruising gear for 5th.

Vote in my poll, or post your experiences here.

Reply #1September 18, 2004, 09:44:21 am

VWRacer

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Which transmission?
« Reply #1 on: September 18, 2004, 09:44:21 am »
Your analysis looks spot-on to me. And since you are able to, do the work once and get it right. I vote for adding 4th and 5th from the 7A into the 4K.
Stan
C-Sports Racer

Reply #2September 19, 2004, 07:33:58 pm

moosiah

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mix'match trannys
« Reply #2 on: September 19, 2004, 07:33:58 pm »
Hi there ...I have a FF in my frankenbunny now and it is a good trans for daily driving/ commuting...... for a higher hp bunny, ie a turbo D bunny a higher geared trans would be desireable ( because diesels are rpm ltd ) so I looked for and found a AON gear box w a 3.67 final and 1.0 4th and .75 5th.... I plan on swapping 4th & 5th for the .91 and .71 from a FF box..... there are tranny code lists on the net that list every gear, CV and final variation available.  I also have a 9y close ratio w a 3.67 final that would be purrfect for a 6sp conversion w a .71 6th  behind a 1.9 TD /TDI ,,,,,,,, when those guys get it together and I'm working on a movie and have money to burn.......... :D
as it is,,, 3rd is good for 55,, 4th to 65 ,, 5th to,,,,,,,,,,,well that would be speeding here in the peoples republic of kalifornia and I wouldn't want the Govenator after me for "wasteing resources" I get best mpg at 63mph. at 75, say on interstate 5 going to LA ,mpg dropped to 40............too many revs.. :(
'81 Frankenbunny: part rabbit, sirroco, golf ,caddy cabrio ,jedda and ! ford teimpo! w a little more Audi and soon some Peogeot too!!!!

Reply #3September 22, 2004, 03:59:46 pm

chrissev

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Re: Which transmission?
« Reply #3 on: September 22, 2004, 03:59:46 pm »
Quote from: "racer_x"
Does anybody actuall vote in the polls here? Or is the poll feature broken?

More questions. I have had a 4K transmission in my 1984 Jetta diesel (1.6D Normally Asthmatic). It's nice from a stop, but the revs are a little high at highway speeds. Also, my highway mileage dropped some with this transmission. I still have the old 7A for parts (diff bearings failed), and I have a few other "parts" transmissions here as well.

I picked up an FN  code transmission and I was going to put that in this weekend. I still might, but I was thinking about maybe making a hybrid transmission that might be better suited to my car and my driving.

I like the tall 5th gear from the 7A (and the FN is pretty tall as well), but I like the closer 1st through 3rd from the 4K. The 4K accelerates much better from a stop through the first three gears. I though about putting the 0.71:1 fifth gear set from my 7A into the 4K, and that would sort of solve the highway revs problem, but the gap from 4th gear (1.13:1) to 5th gear (0.71:1) would be huge. If I needed to drop to 4th on the highway for some reason, it would be pretty useless.

The last option I'm considering is putting 4th and 5th from the 7A into a 4K. That's more work because the main case has to be opened, but I could also throw a bolt kit in while I have it apart and make it pretty much bullet proof for the diesel. That would give me good acceleration from the stoplight with the close ratio 1st, 2nd and 3rd. It would give me an "economy" gear for city streets in 4th (0.91:1) which would double as a hill climbing and "passing" (yeah, right) gear for the highway. And, finally, I'd have the highway cruising gear for 5th.

Vote in my poll, or post your experiences here.


Avoid the 4K with .89 fifth at all costs.  Highway cruising sucks with this gearbox (unless you like turning 4000+ rpm at 70mph.)
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now

Reply #4September 22, 2004, 05:22:18 pm

racer_x

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Re: Which transmission?
« Reply #4 on: September 22, 2004, 05:22:18 pm »
Quote from: "chrissev"
Avoid the 4K with .89 fifth at all costs.  Highway cruising sucks with this gearbox (unless you like turning 4000+ rpm at 70mph.)
Well, I had the 4k with the 0.89:1 fifth in it for several months. It beat parking the thing, but highway speeds were loud and droning.

Reply #5September 22, 2004, 10:25:01 pm

Blades

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Which transmission?
« Reply #5 on: September 22, 2004, 10:25:01 pm »
I have the AWY, similar to the 4K

It's loud and rev like *** but it's fun.

I got used to it over the years. It's actualy less annoying than my 1.8 8v turning 3000 rpm @ 100km/h

The 4K is well suited for the 1.6D.

It goes against all theories but it's got great 5th gear pull.

Reply #6September 23, 2004, 11:26:01 am

chrissev

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Which transmission?
« Reply #6 on: September 23, 2004, 11:26:01 am »
Quote from: "Blades"
I have the AWY, similar to the 4K

It's loud and rev like *** but it's fun.

I got used to it over the years. It's actualy less annoying than my 1.8 8v turning 3000 rpm @ 100km/h

The 4K is well suited for the 1.6D.

It goes against all theories but it's got great 5th gear pull.


problem with the .89 fifth in those transmissions is it wears out your engine much quicker.  You can get 250,000km out of an AWY equipped diesel 1.6 or twice that amount almost out of say an AGS or similar transmission.
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now