honda305.com Forum

Vintage Honda Owners, Restorers, Riders and Admirers

Latest Registry Entry
1965 Honda CP77 — Ulsan Metro City, Rep. Korea
Restored with original parts — Owner: J. Doe

Need help identifying transmission issues

Clutch, Transmission, Drive Chain, Sprockets
Post Reply
AZscrmblr
honda305.com Member
Posts: 27
Joined: Sat Sep 16, 2017 7:29 am
Location: Phoenix AZ

Need help identifying transmission issues

Post by AZscrmblr » Wed Oct 25, 2017 10:21 am

I have a noise that I believe is coming from the transmission (see my post “Transmission noise” in the CL72/CL77 forum). In addition, it is becoming difficult to shift from 2nd to 3rd . It does not want to engage 3rd gear until you lift the shift lever a second time. I decided to split the engine cases and do some investigation. I have included some pictures and what I have observed thus far. I would appreciate it if someone with knowledge of the types of problems to look for in the transmission could give me some feedback.
It looks to me like the dogs on the counter shaft 3rd gear are somewhat rounded (1st photo). Are they rounded enough to cause the dogs from the 2nd gear to not engage until the shift lever is lifted a second time?
When in 2nd gear, the dogs don't appear to engage fully by the movement of the shift fork (2nd photo). They can be brought closer together with your fingers (3rd photo). When power is applied through the main shaft does the taper of the engaging dogs of any two gears pull them together?
Would it be beneficial to install offset cotters?
Any other feedback from looking at the pictures?


ImageDSC04198 by Gary Snell, on Flickr

ImageDSC04201 by Gary Snell, on Flickr

ImageDSC04204 by Gary Snell, on Flickr
Top
LOUD MOUSE
honda305.com Member
Posts: 7818
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Re: Need help identifying transmission issues

Post by LOUD MOUSE » Wed Oct 25, 2017 4:28 pm

The gears look OK to me.
I'd bet the problem is a warn point and roller at the shift drum. .............lm

AZscrmblr wrote:I have a noise that I believe is coming from the transmission (see my post “Transmission noise” in the CL72/CL77 forum). In addition, it is becoming difficult to shift from 2nd to 3rd . It does not want to engage 3rd gear until you lift the shift lever a second time. I decided to split the engine cases and do some investigation. I have included some pictures and what I have observed thus far. I would appreciate it if someone with knowledge of the types of problems to look for in the transmission could give me some feedback.
It looks to me like the dogs on the counter shaft 3rd gear are somewhat rounded (1st photo). Are they rounded enough to cause the dogs from the 2nd gear to not engage until the shift lever is lifted a second time?
When in 2nd gear, the dogs don't appear to engage fully by the movement of the shift fork (2nd photo). They can be brought closer together with your fingers (3rd photo). When power is applied through the main shaft does the taper of the engaging dogs of any two gears pull them together?
Would it be beneficial to install offset cotters?
Any other feedback from looking at the pictures?


ImageDSC04198 by Gary Snell, on Flickr

ImageDSC04201 by Gary Snell, on Flickr

ImageDSC04204 by Gary Snell, on Flickr
Top
AZscrmblr
honda305.com Member
Posts: 27
Joined: Sat Sep 16, 2017 7:29 am
Location: Phoenix AZ

Post by AZscrmblr » Wed Oct 25, 2017 5:28 pm

Loud Mouse – Thanks for the feedback. I will remove the guide pins and rollers, take some pictures and post them here.
Top
LOUD MOUSE
honda305.com Member
Posts: 7818
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Post by LOUD MOUSE » Wed Oct 25, 2017 6:30 pm

Also show the point in the slot closest to the end with the neutral switch slot. .............lm
AZscrmblr wrote:Loud Mouse – Thanks for the feedback. I will remove the guide pins and rollers, take some pictures and post them here.
Top
AZscrmblr
honda305.com Member
Posts: 27
Joined: Sat Sep 16, 2017 7:29 am
Location: Phoenix AZ

Post by AZscrmblr » Thu Oct 26, 2017 1:36 pm

Here are some photos of guide pins, rollers and shift drum points.

ImageDSC04213 by Gary Snell, on Flickr

ImageDSC04214 by Gary Snell, on Flickr

ImageDSC04219 by Gary Snell, on Flickr

ImageDSC04220 by Gary Snell, on Flickr

ImageDSC04217 by Gary Snell, on Flickr

ImageDSC04218 by Gary Snell, on Flickr
Top
AZscrmblr
honda305.com Member
Posts: 27
Joined: Sat Sep 16, 2017 7:29 am
Location: Phoenix AZ

Post by AZscrmblr » Thu Oct 26, 2017 5:00 pm

I decided to replace the 14mm bushing while I had the transmission open. When I compared the old bushing to the new one I found that there is a difference in the ridge in the center of the bushings (1st photo). The old one is thinner and has a taper on the side that goes into 1st gear (bushing on right in 1st photo). The taper matches a taper in the gear (2nd photo). The new bushing is flat on both sides of the ridge. When it is put inside the 1st gear, it does not go in as far (3rd photo).
Is this going to cause a binding problem? I did a search on the bushing and found quite a lengthy discussion but am not certain as to the final conclusion.

ImageDSC04228 by Gary Snell, on Flickr

ImageDSC04231 by Gary Snell, on Flickr

ImageDSC04233 by Gary Snell, on Flickr
Top
LOUD MOUSE
honda305.com Member
Posts: 7818
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Post by LOUD MOUSE » Thu Oct 26, 2017 5:01 pm

All parts lok good.
How is the shift drum keeper installed?. ...........lm

AZscrmblr wrote:Here are some photos of guide pins, rollers and shift drum points.

ImageDSC04213 by Gary Snell, on Flickr

ImageDSC04214 by Gary Snell, on Flickr

ImageDSC04219 by Gary Snell, on Flickr

ImageDSC04220 by Gary Snell, on Flickr

ImageDSC04217 by Gary Snell, on Flickr

ImageDSC04218 by Gary Snell, on Flickr
Top
Post Reply

Return to “Transmission”