mavguy
L plate rider.
Posts: 18 
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Post by mavguy on May 9, 2020 19:25:34 GMT 1
Hello folks, just been in a fix.I came across this ebay post listing a RD250 air cooled transmission and claiming it to be the same as the ones used in RD400.now AFAIK both transmissions are different but the funny thing is that the splines on the main shaft seem to be the same?anyone knows what I am missing out on?
Thanks.
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Post by dusty350 on May 9, 2020 20:21:50 GMT 1
Hi They are the same, model for model, so 250e same as 400e, etc Dusty  |
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Post by dusty350 on May 9, 2020 20:22:55 GMT 1
Clutch and primary drive gears are different between 250 and 400 though Dusty |
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mavguy
L plate rider.
Posts: 18
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Post by mavguy on May 10, 2020 2:51:31 GMT 1
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Post by dusty350 on May 10, 2020 7:41:36 GMT 1
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Post by reedpete on May 10, 2020 10:47:34 GMT 1
Ok so ...
There were two clutch spline patterns, early and late...crossover at RD250/400C
So that listing description is vague /wrong , in that that cluster is not actually 73-75 but if you had the other clutch and gear parts could be put on an early bike.
From the picture alone I cannot tell if that is for C/D or E/F, and you can’t mix them, also not ideal that it’s a single cluster, would be better to change as a pair.
If you need C/D clusters expect to pay £65 for both shafts from either if the two breakers. , Andy Jones or RD James.
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Post by reedpete on May 10, 2020 11:04:14 GMT 1
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mavguy
L plate rider.
Posts: 18
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Post by mavguy on May 10, 2020 12:20:43 GMT 1
Well I am in need of a RD400 trans.
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Post by reedpete on May 10, 2020 12:28:41 GMT 1
250 is same as the 400 , you just need to make sure you get the correct year. Only two options c /d, E/F.
What bike do you have ?
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Post by reedpete on May 10, 2020 12:31:35 GMT 1
Just in case it’s not 100% clear...there are two different RD400 gearboxs and the clusters will not mix ...so you simply need to know what you have.
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mavguy
L plate rider.
Posts: 18
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Post by mavguy on May 10, 2020 12:38:48 GMT 1
250 is same as the 400 , you just need to make sure you get the correct year. Only two options c /d, E/F. What bike do you have ? I am converting my RD350 air cooled to a TZ liquid colled alongwith using a 400 transmission. |
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Post by reedpete on May 10, 2020 12:53:25 GMT 1
Oh....the plot thickens !!
..I need more info before I can give you the data you need, ‘convert to tz’ can mean a lot if things...TZ top end but wet clutch ? , TZ everything except the actual gears on the two clusters....
5 min chat will close this.
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Post by dusty350 on May 10, 2020 14:09:44 GMT 1
I still have the 400e transmission I took out of my engine. It had corrosion on a couple of the gears, and I luckily picked up a mint low mileage set to replace rather than strip the originals down.
Doesn't sound like they will match your 2/350 though
Dusty
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Post by reedpete on May 10, 2020 14:16:52 GMT 1
E/F gears would be the best to use on a TZ shafts. Most are the same but 6th got beefed up a bit.
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mavguy
L plate rider.
Posts: 18
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Post by mavguy on May 10, 2020 14:39:58 GMT 1
Ok. I think I got things muddled.
I have a RD350B engine to start with:
1) will be chopping and welding to make it a 4 cylinder. Most probably using TZ750 cylinders.
2) want to swap the 350 transmission with that of a RD400 for better gear ratios and use of the banshee hub.
3) not going to use a dry clutch , so the main shaft stays the same.
Regards
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Post by Bryan H on May 10, 2020 19:40:59 GMT 1
If your 350 is a Euro (521) model then you already have the close ratio gearbox. Have a read of the attached link RD Gearbox Update |
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Post by reedpete on May 10, 2020 19:55:46 GMT 1
It’s a USA engine
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Post by chrisg on May 10, 2020 20:57:19 GMT 1
That's Dave James, I have bought stuff from him. Top guy and trustworthy. He has even sent me stuff on a sale or return basis, you cant get better than that.
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