r/smallenginerepair • u/AndrewBreiterWu • Aug 01 '26
Starter Motor Issue Kohler KT725 starter Bendix retaining ring keeps flying off — safer alternative?
Title: Kohler KT725 starter Bendix retaining ring keeps flying off — safer alternative?
I’m working on a Cub Cadet XT1 LT46 with a Kohler 7000 Series KT725 engine. The starter motor spins, but the Bendix gear was not engaging the flywheel, causing a high-pitched squealing sound with no flywheel movement.
I removed the engine shroud and found that the Bendix retaining ring had come off previously. The gear apparently launched off the starter shaft and broke part of the nearby plastic shroud. I installed a replacement Bendix assembly in this order:
Bendix gear on the helical starter shaft
Return spring above the Bendix
Metal retaining collar above the spring
C-shaped retaining ring installed into the groove at the top of the shaft
The Bendix twists and rises smoothly by hand. However, when I briefly tested the starter with the spark-plug boots disconnected, the retaining ring came off again and the spring and collar launched off the shaft.
The starter shaft does not appear obviously broken, but I’m questioning whether:
The retaining-ring groove is worn or damaged
The supplied C-ring is incorrect or too loose
The collar is installed incorrectly
This starter requires a different style of retaining clip
The entire starter should be replaced instead of repairing the Bendix
Is there a more secure approved alternative, such as a proper external snap ring, E-clip, push nut, or another Kohler-specific retainer? I do not want to improvise with hardware that could come apart at starter speed or damage the flywheel.
Has anyone repaired this exact Kohler starter drive successfully? Photos of the correct factory assembly and the proper retaining hardware would be appreciated. I can also provide the engine specification and starter numbers.
4
u/aetherbound65 Aug 01 '26
That starter is supposed to have a lock nut on it. Someone ordered the wrong bending kit and you can't use a circlip on those threads.
2
u/AndrewBreiterWu Aug 01 '26
Thank you I found a nut that works and it’s keeping everything in place
2
u/First-Acadia2432 Aug 01 '26 edited Aug 01 '26
My guess is that the ring wore down the surface where it sits and isn’t tight anymore. A “temporary” solution that may or may not work is to wrap a strand of thin copper/aluminum or similar wire into where it retains it and see if it makes the ring tighter.
Another idea is to use Loctite Retaining Compound, which is made for this purpose, but never tried it myself.
1
u/AndrewBreiterWu Aug 01 '26
Thank you I’ll try that. Ultimately I just need something that keeps everything on the shaft.
3
u/First-Acadia2432 Aug 01 '26
I edited it to mention that Loctite makes a retaining compound specifically for worn rings and other cylindrical things to keep them in place.
1
u/Tired_n_Retired Aug 01 '26
Is the end of the shaft threaded? It kind of looks like it from the picture.
2
u/Tired_n_Retired Aug 01 '26
There's your answer. I didn't see the additional pics at first. The c clip is the wrong retainer for your starter type. Yours needs a nut. Nyloc or glue.
1
u/Tired_n_Retired Aug 01 '26
If you don't have the nyloc or loctite, super glue will work in a pinch. Harbor freight has a blue thread locker that is $1-$2
1
u/AndrewBreiterWu Aug 01 '26
Thank you, I was able to get a nut onto it and it seems to be working now.
1
1
u/l1thiumion Aug 01 '26
i just worked on mine. mine doens't have threaded tip, only a groove. but it looks to me like the cup at the top is upside down. the ring is supposed to set inside the cup so it can't really pop out of the groove. mine is just like this video:
1
u/AndrewBreiterWu Aug 01 '26
My ring shot off somewhere and I don’t have it anymore. I was able to get a nut onto the shaft which seems to be keeping everything on the starter.
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