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RB20DET Gearbox Question
Posted: June 6th, 2010, 10:01 pm
by nemesis_7514
different rb20's come with different gearboxes, more specifically they are numbered (#1, #2, #3, .....etc)
can anyone shed some light on the specific differences between each one
and the possible pros and cons, maybe even best possible application (drag, drift.....) for each
Re: RB20DET Gearbox Question
Posted: June 13th, 2010, 6:21 pm
by Blackbyrd
There are the gear boxes that come from the turbocharged and non turbo RB20 engines.
The part numbers are as follows:
RB20DET Gearbox - RB71C (some come with a kangaroo logo) This is gear box has the stronger synchros, etc, if you can afford it, buy it!
RB20DE Gearbox - RC71 ( I stand to be corrected ) This is the non turbo gear box. It can work on the RB20DET but it has weaker synchros and will not last long due to hard or aggressive gear changes/driving. When the synchros are bad you will experience a grinding sound in between 1st to 2nd and 3rd gear changes.
The RB25 gearbox can work but I believe the flywheel has to be changed.
Re: RB20DET Gearbox Question
Posted: June 14th, 2010, 8:36 pm
by nemesis_7514
i believe that the RB71C gearboxes come from turbo rb's in r31 skylines, etc.
the RP71C comes from r32, a31, c33, etc
i have two gearboxes on the ground
one has RP71C #1
and the other has RP71 #2
Both came off original a31 cefiro's (both being turbocharged and manual)
i was also told that there is RP71C #4 but this comes with the RB28 diesel engine
Does the #1 and #2 after the gearbox code signify any kind of difference in gearbox internals, ratios, strength
Re: RB20DET Gearbox Question
Posted: June 14th, 2010, 11:59 pm
by Blackbyrd
The gearbox that was damaged in my car was a RP71 gearbox. As far as I know this gearbox came out of non turbo engines and was the weaker gearboxes. I replaced it with a RB71C gearbox with the kangaroo logo. I did my research before I bought it and the info I got stated that it came out of the R32GTS-t two door skyline. The gear box was installed with new copper clutch, pressure plate, pilot busching , clutch release bearing and oil. It worked very well with no problems.
Honestly I wouldn't use a RP71 gearbox, I am not saying it can't work, it will work just fine, it just can't handle the rough and aggressive gear changes from my experience.
Browse other skyline forums and get more feedback and info from other owners
Re: RB20DET Gearbox Question
Posted: June 16th, 2010, 12:25 am
by nemesis_7514
did some digging on the forums and from what i gathered,
the rb20det comes with both rb71c and rp71c gearboxes,
some people say they have the rp and some have the rb
don't know if one is just newer that the other
got this on one of the forums
'RP71C #2', the ratios are 3.32, 1.9, 1.31, 1.0 and .838.
these ratios matches the nissan factory service manual for the rb20det manual transmission, (the gearbox for the na engines has a different ratios set)
however the manual makes no mention of RP71C or RB71C
Re: RB20DET Gearbox Question
Posted: June 16th, 2010, 12:31 am
by nemesis_7514
but the real question i'm asking is not whether the RB71C is better than the RP71C or vice versa (Quite frankly i'm beginning to believe they are the same blasted thing), but what does the #1 and the #2 mean after the code, if anything at all
Re: RB20DET Gearbox Question
Posted: June 16th, 2010, 12:40 am
by nemesis_7514
Model Engine 1st 2nd 3rd 4th 5th
R32 GTE 5 Speed RB20E 3.321:1 1.902:1 1.308:1 1:01 .838:1
R32 GTS 5 speed RB20DE 3.321:1 1.902:1 1.308:1 1:01 .759:1
R32 GTS-t 5 Speed RB20DET 3.321:1 1.902:1 1.308:1 1:01 .759:1
Both twin cam engines (turbo and n/a) have the same gearbox ratio specs
Re: RB20DET Gearbox Question
Posted: June 16th, 2010, 6:19 pm
by Blackbyrd
Maybe the numbers have something to do with the years of manufacture. I am not sure. But the important thing is you have two gear boxes so just install and drive.
Re: RB20DET Gearbox Question
Posted: June 16th, 2010, 7:56 pm
by nemesis_7514
thanks man, appreciate the input