Topic: 1978 CB750A Input Shaft Springs

[LiveeviL81]

Hey Guys,
Looking over my transmission parts before reassembly and noticed I had some broken springs on a gear in what the manual calls the Input shaft.
What is the best way to get a replacement/repair?

https://www.partzilla.com/catalog/honda/motorcycle/1978/cb750a-a-750-hondamatic/low-clutch-mainshaft
Part 10

Any other known failures on the transmission side to check? I have been scared to open up the clutch packs for Low/Drive because I don't have a good spring compressor.

Thanks, Kaleb

[LiveeviL81]

Found a link to what seem to be replacement ones on Ebay, is there a guide on how to tear open it replace these? Is it a difficult process?

https://www.ebay.com/itm/331671472951?itmmeta=01HPJQKY1KMVP9482TJ9EBHQJT&hash=item4d39290b37:g:LbIAAOSwLF1X48mQ&itmprp=enc%3AAQAIAAAAwHIpIoyrOP6SEPzE%2Fh1hh7enptZqQgeKN7yt06SQcLzT%2BBi%2FgI2sxqn9JR8eSv2kFyLgAclE9c%2B4ILFditPc30LwHc1C99VgcAon5wq3aA4PnDx%2B%2B83zntKOwO9rxjNcE%2FPmlNfugQS2V%2F6tCTRvWdr6SqZp04FLX3pXlB6LBXyotRjB7pUrQtCvJNXhbt%2B0z7dxUeaShQU7M2ZB66I6xnDvz%2BL0%2BsDxRznCF7bZILs3wvVvUeAXcuAyjRAi137JTg%3D%3D%7Ctkp%3ABk9SR_Lgz9e0Yw

[jukku]

Hey Guys,
....................
.................
Any other known failures on the transmission side to check? I have been scared to open up the clutch packs for Low/Drive because I don't have a good spring compressor.

Thanks, Kaleb

You dont need any spring compressor because the clutches are hydraulic operated.
The input shaft springs are "damper" springs.
Common sense is the best tool when you open the "thight fits", you dont need special tools.

[LiveeviL81]

To get to the damper springs, it looks like I need to take apart the torque converter and press the input shaft out from it interfaces with the "Pump." Though in the manual it shows a Bearing Driver Attachment used to disconnect the "Pump" from the "Cover" when still attached to the bike, is there something stopping me from pressing these two apart in a hydraulic press?

[LiveeviL81]

Hey Guys,
....................
.................
Any other known failures on the transmission side to check? I have been scared to open up the clutch packs for Low/Drive because I don't have a good spring compressor.

Thanks, Kaleb

You dont need any spring compressor because the clutches are hydraulic operated.
The input shaft springs are "damper" springs.
Common sense is the best tool when you open the "thight fits", you dont need special tools.

The manual shows that you are supposed to use a clutch spring compressor tool to be able to remove the snap ring. I could probably jig something up similar with some bolts/plates.

[MRieck]

Those "square" springs are broken in every auto engine I've seen. It's something you can bank on. How they break with a 40-45HP engine is beyond me. I've replaced them using a press.
 I'd check those drive plates....they are as old as dirt and probably the same consistency. I got new ones from Transtar I think.

[LiveeviL81]

Those "square" springs are broken in every auto engine I've seen. It's something you can bank on. How they break with a 40-45HP engine is beyond me. I've replaced them using a press.
 I'd check those drive plates....they are as old as dirt and probably the same consistency. I got new ones from Transtar I think.

Not a bad call, I'll have to do some digging to find more of those plates. I've heard they are hard to find.

Update:
Ended up measuring each of the plates and comparing them to the manual. Looks like they all have about 3-5 thou over the service limit. I'm no expert on friction pads but they look uniform and no burns, discoloration, or anything missing.

Checking the forum for replacement's, all of the websites I saw were no longer available. Ebay was no luck either. May call Transtar Monday,

[MRieck]

Those "square" springs are broken in every auto engine I've seen. It's something you can bank on. How they break with a 40-45HP engine is beyond me. I've replaced them using a press.
 I'd check those drive plates....they are as old as dirt and probably the same consistency. I got new ones from Transtar I think.

Not a bad call, I'll have to do some digging to find more of those plates. I've heard they are hard to find.

Update:
Ended up measuring each of the plates and comparing them to the manual. Looks like they all have about 3-5 thou over the service limit. I'm no expert on friction pads but they look uniform and no burns, discoloration, or anything missing.

Checking the forum for replacement's, all of the websites I saw were no longer available. Ebay was no luck either. May call Transtar Monday,

Cost was very reasonable from Transtar. Those frictions fit the Early Honda Civics.