HRR216, Cleaned shaft, still won't roll backwards

[gossamer]

Hi, I have an HRR216 S3DA MZCG-6078970 basic lawn mower that I picked up at the curb. After getting it to start again, I realized that it doesn't roll back on its own and doesn't go forward under load when the self-propel system is engaged. I've followed a few videos demonstrating how to take the rear end apart and clean it thoroughly, including taking the snap rings and pinion gears out, carefully cleaning and sanding the rust from the axle, then reassembling it. However, it still doesn't go back easily. I'm wondering what the next steps would be?

Even when suspended off the ground, the tires don't really spin as freely as I feel like they should. It goes forward in all three gears when I suspend it off the ground and engage the self-propel system, so I don't think it's the belt or the transmission. The height adjuster also now moves freely as it should. I also don't see any way to adjust the cable that engages the self-propel system arm, thinking maybe it wasn't engaging the belt fully.

I'm also now able to turn the axle freely by hand. I've also confirmed the pinion gears on both sides are in good shape, as are the gears in the wheels, so the transmission is definitely engaging with the wheels.

Could it be the driveshaft bushing? There seems to be a bit of side-to-side play in the wheel. I've put together a 60s video showing this problem:

HRR216-real-wheel-play.mp4

drive.google.com

Here's a link to the parts diagram for the rear wheel

https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/honda/lawn-mower/hrr216-s3da-lawn-mower-usa-vin-mzcg-6000001-to-mzcg-6299999/rear-wheel-1

How smooth does the axle where the bushings go really have to be? It didn't appear like the axle was very bad, so I didn't remove it entirely. I only cleaned it and sanded it with 220-grit with it still in the chassis.


Ideas are greatly appreciated.

 

[PTmowerMech]

# 8. 3 speed tranny. $122.

I've dabbled into taking these push mower tranny's apart and trying to fix them. Everything seems simple enough on the inside. But I don't think I've ever actually fixed one.
Never tried a honda one though.

 

[gossamer]

I'm reluctant to get involved with trying to rebuild the transmission until/unless I can be sure.

Is there any alternative at this point? Does it really sound like the transmission is the problem here? How can I test it before taking it apart?

 

[PTmowerMech]

I'm reluctant to get involved with trying to rebuild the transmission until/unless I can be sure.

Is there any alternative at this point? Does it really sound like the transmission is the problem here? How can I test it before taking it apart?

Remove the belt to make sure that's not the issue. Remove the tranny and turn the axles by hand. This will eliminate any binding that may be coming from it being mounted. And you can check the travel on the levers coming out of the tranny. Maybe one has built up too much dust and dirt, and it's not allowing it back into a neutral position. After that, there's nothing left except something wrong inside the tranny.

 

[gossamer]

Remove the belt to make sure that's not the issue. Remove the tranny and turn the axles by hand. This will eliminate any binding that may be coming from it being mounted. And you can check the travel on the levers coming out of the tranny. Maybe one has built up too much dust and dirt, and it's not allowing it back into a neutral position. After that, there's nothing left except something wrong inside the tranny.

I've now got both wheels and wheel assemblies off and the axle does spin freely. The axle looks to be pretty clean and free from rust or pits that would cause it to bind in the wheel bushing. I've also removed and inspected the belt and it doesn't appear to be dried out or cracked or shiny. I do have another, but I also don't think that's the problem either, as it doesn't look terrible.

I've removed the spring that was supporting the transmission in the chassis, but I can't figure out how to remove the transmission gear shift cable so I can try to manually change gears separately from the shift lever connected to the handle. I've produced a video to show what it looks like. Would you have a few minutes to review? I'm also happy to provide any other info - different angles or pictures, etc.

Honda-HRR216-Transmission.mp4

drive.google.com

 

[Tiger Small Engine]

I've now got both wheels and wheel assemblies off and the axle does spin freely. The axle looks to be pretty clean and free from rust or pits that would cause it to bind in the wheel bushing. I've also removed and inspected the belt and it doesn't appear to be dried out or cracked or shiny. I do have another, but I also don't think that's the problem either, as it doesn't look terrible.

I've removed the spring that was supporting the transmission in the chassis, but I can't figure out how to remove the transmission gear shift cable so I can try to manually change gears separately from the shift lever connected to the handle. I've produced a video to show what it looks like. Would you have a few minutes to review? I'm also happy to provide any other info - different angles or pictures, etc.

Honda-HRR216-Transmission.mp4

drive.google.com

I appreciate that you are trying to fix this issue. Must be that you have the time, interest, and motivation because going in deep on a 15 year old self-propelled gearbox is unusual. Gearbox seems fine if you have it free like that and it is spinning so problem is elsewhere.

 

[gossamer]

I appreciate that you are trying to fix this issue. Must be that you have the time, interest, and motivation because going in deep on a 15 year old self-propelled gearbox is unusual. Gearbox seems fine if you have it free like that and it is spinning so problem is elsewhere.

But don't you just want to know why it stopped working?

Yes, it's more for the challenge. And the sense of accomplishment when I get it done. It's a nice break from my very stressful day job. I've been fiddling with it since at least May. I started by replacing the carb, thinking that's usually enough. I'll make sure the axle is clean and the belt pulleys are clean, perhaps run some oil down the gear shift cable, put it back together, and hope it works.

 

[Scott_HRR]

I just did this service to my HRR216 after owning it for about 10 years. I completly removed the transmission and shaft so it could be cleaned. The bushings looked ok, but I ran a nylon brush soaked in penetrating oil through them To make sure they were 100% clean. Pinion gears springs and woodruff keys were soaked in gas overnight. When I put everything back together the only thing I greased was the shaft where it rides on the bushings. Everything else was just lightly oiled. I have found when you grease everything Honda recommends you end up attracting so much dirt and grass it’s more detrimental than if you did no maintenance. My drive shaft bushings were tight so I did not replace them. It’s hard to tell from your video but to me at least it seems like you have more play than their should be, so I’d replace the bushings —> Honda 44327-VG3-B00 Drive Shaft Bushing Genuine Original Equipment Manufacturer (OEM) Part https://a.co/d/0dgqIqi
Also do the seals while you are there —> Honda 42944-VE2-801 Dust Seal (12.7Mm) https://a.co/d/fMGMewA

When rolling backwards even when things are working properly there is some resistance vs. pushing forward. Once a tire starts to slide on a smooth service when pulling backwards it’s time to service everything.

Also on the pinion gears, they have dot on the face. On one wheel the dot needs to face out and on the other wheel it needs to face in. I’d tell you which but I forgot and don’t want to give you bad information, just look it up. If your trans spins freely but the mower won’t drive forward, either the belt tensioner isn’t working or the pinion gear (Dots) orientation is not correct.

 

[dawgn86]

I did this to my 10 year old Honda last spring. Took everything out, replaced the belt, pinion gears and changed the transmission oil. Sanded the shafts down and put it back together. Worked great up until last week or so and starting to bind again.