Topic: Transmisssion Info Needed Please

[bwaller]

Hey all, can anyone give me the total length of a 400F transmission mainshaft? I believe that MS first gear is 24T?

[bwaller]

Looking to see if a 400F mainshaft might be shoehorned into 550 cases.
 
I have a parts bike I can tear down, but thought if someone had one apart to measure first.......

[bikebitzofvt]

I have a 77 400F bottom end sitting on the shelf with the intent of breaking it for parts.  I'll try to get it torn down on Monday and post the results.  I think I recall reading here or elsewhere that the 400F 6 speed would not fit in the 550 cases but I can't remember the details.  I also have a 79 CB650 freshly torn down if you need any measurements or cog counts from that. 
T

[paulages]

brent- billy's got one in a box somewhere at the shop. i'll look for it when i'm there this afternoon. anything else you need to know about it? just total length of the MS?

[bwaller]

T, Don't tear it apart on my behalf, and I know that 6spd won't fit, plus I have a 650 g-box here on the bench as well as several others. 

I am curious if the 400 mainshaft is too long to fit. (the 360 6spd MS sure is)

Paul if you find one I only need total length, if it looks like it'll co-operate I'll dynamite one out of a parts bike.

Thanks guys

[paulages]

T, Don't tear it apart on my behalf, and I know that 6spd won't fit, plus I have a 650 g-box here on the bench as well as several others. 

I am curious if the 400 mainshaft is too long to fit. (the 360 6spd MS sure is)

Paul if you find one I only need total length, if it looks like it'll co-operate I'll dynamite one out of a parts bike.

Thanks guys

well brent, you're wrong about one thing: total length is not all you're looking for; you also need 1st gear to be in the right place. the 400 shaft does in fact measure the same in total length, but bearing-to-bearing the shaft is shorter. in other words, the fixed first gear is in the wring place to work with the other transmissions. here's a pic next to a 650 mainshaft:



i'm wondering though: could a competent welder weld in that 400 gear in the right spot?

P.S.: who can name the model repair manual open in the background? 

[turboguzzi]

well, if you move the whole shaft right so first is aligned, then it means that overall, the 400-6spd cluster is narrower.

all you have to do is EXTEND the left end of the shaft and put a spacer to fill the space

mmmm

Paul, Brent, posting something interesting in the perf section, have  a look

TG

[bwaller]

Yea guys, nothing will be a direct fit but as long as the total shaft length is close it might work.

I have an 82 CB450 6 spd that might also lend a shift drum & counter shaft to the cause.

[bryanj]

BE CAREFULL, just cos the number off teeth is the same dont mean it will mesh right, not sure exactly what the terminology is but Honda changed the shape (Pitch?) of the tooth profile so that you have to use the correct mating gear.
I assembled a box for a 500 using 500/550/650 parts and it was a damn nightmare!!

[paulages]

Yea guys, nothing will be a direct fit but as long as the total shaft length is close it might work.

I have an 82 CB450 6 spd that might also lend a shift drum & counter shaft to the cause.

i'm curious how you'd make it work, but keep it up! can't wait to see you figure out a CR gearbox out of OEM parts. 

[kayaker43]

I'm watching this too..

I have heard the same thing bryanj is talking about. For instance, a 17/24 and 17/23 combo can be made to fit the same shaft spacing by altering the tooth profiles. Therefore they have to be used in pairs and can't be mixed up,.. a 17 from one won't fit the other! Of course I made up those numbers but you get the idea.

I don't know if its true, but I kinda believe it? We might have to use matching pairs when mixing up oem gearboxes, but a gear maker may be able to make a custom gear one tooth off?

[bwaller]

With narrower gears only 2/3 of that MS 1st makes contact so it's width could be reduced for instance.

I completely agree with using matching gearsets. Making wholesale changes isn't logical, and finding the path to calculate improvement is difficult. I may ask for ideas at some point.

I'm up to my armpits in transmissions from different engines and this may not even turn out well, but it's a cool project.... I'm with TG, spending outta sight money on a g-box isn't in the cards.

Once I get this apple harvest in I'll have some more time. 

Stand by.

[paulages]

Once I get this apple harvest in I'll have some more time. 

Stand by.

high-performance braeburns?