QA42A snow-blower on 82-series, gearbox alignment question

[cmiller]

Hi all....

I have a QA42A on a 782. I believe the blower is older than the tractor, since it is marked "International Harvester" and the tractor is marked "CCC." I don't remember the exact details (I was a kid), but I recall it was set up by a Cub dealer, and delivered to my dad roughly 40 years ago. It does have the curved upper links, which I understand are in consideration of the 82-series frame shape.

I have recently disassembled the whole thing for a little love and restoration, and upon inspection and consideration (and a few beer), I developed a certain curiosity....

Since the engine is set at a slight angle to the chassis on the 82-series, and the support frame positions the right-angle gearbox square to the frame, the engine and the gearbox are not truly parallel. It's not been an issue, but the engineer in me is bothered by this. I expect that two shafts joined by a belt should be parallel to each other. I believe the earlier 1XX series of tractor (on which this blower was originally used), the engine is mounted square to the frame, so this would not have been an issue.

I wonder whether this was ever addressed by Cub Cadet with some kind of Technical Service Bulletin and/or "update kit," to the effect of, "When using a QA42A on an 82-series, install kit number XYZ"? Or was this situation just allowed to exist with no harm? Or am I off my rocker, and I am not looking at the issue correctly?

I'd appreciate any thoughts or insight.

Thanks,
Chris

 

[mgonitzke]

I have basically the same setup on my 782. I had issues with it throwing the belt all the time until I made some new spacers for the bolts where the gearbox plate slides to tilt the gearbox plate about 2 degrees to match the engine tilt, and it has worked great ever since.

Most people seem to get away with it without doing this, but mine never worked right until I modified it.

 

[cmiller]

Thanks for your response, Matt. I think I'm gonna do something like that. Maybe get some leveling washers (they swivel to allow a misalignment) from McMaster-Carr, or 3D-print some kind of wedge plates.

Does anyone know the theoretical angle (e.g., have access to some old engineering drawings from CC)? I was thinking of measuring the angle of the transaxle relative to the frame (just because it seems easy enough to measure), and assume that they are parallel.

 

[mgonitzke]

I tried to measure it when I modified mine. IIRC 2-2.5 degrees. Probably a bit of variation from unit to unit given that that engine mount plate is stamped.

If you measured from the center of the trans input shaft and the center of the driveshaft coupler on the flywheel from a common plane like the bottom of the frame, you should be able to determine it fairly accurately.

 

[mgonitzke]

Here's an old pic with my tapered washer spacers installed.

 

[hydroharry]

Matt and Chris - this is one of the best threads I've read in a long time. First off I never heard of the 782 engine misalignment with the frame and really questioned whether this was true, but then Matt jumps in and confirms, and from experience no less with the exact same equipment. Doesn't get better than that.
Kudos to both you guys for some great info.
Sometimes it's hard to believe you actually do learn something new.
Hydro Harry
Old Cubs Never Die

(under edit) Matt - if I recall correctly under the old Forum didn't your profile note you were an aeronautical engineer? Nice to see you're flying high now. Those QA42A's do really blow!

 

[cmiller]

Thank for the picture and follow-up, Matt.

I extensively disassembled and reverse-engineered (measured everything I could) on my 2072 to put it into SolidWorks, but did not yet do this for my 782. For the 2072, I came up with 3.36° for the engine installation angle (this is subject to my inaccuracies during the measuring process, but I did cross-check a number of features to try to get the best answer through averaging). I did not go so far as to remove the engine to isolate/measure the angle of the mounting plate directly. This seems like the best source of he information; it's just hard to get to.

I'm now further intrigued because, upon a look-up exercise in PartsTree.com, I learned that the engine mounting plates are the same for both the GT's and SGT's, PN 703-1078... But since the SGT frame is longer, this seems to suggest a conflict in terms of giving both tractors the "correct" engine-to-transaxle alignment OR, the IH engineers just figured it was close enough, and the fabric/rubber driveshaft couplers would allow for a slight misalignment.

I am going to try to measure some of the affected features/components on the 782, and I'll report what I find.

Above all, thanks for the interesting discussion!

 

[cmiller]

Today I measured the driveshaft and the transaxle housing angles relative to the fame on the 782, and I'm getting somewhere between 3.5° and 4.5°. Again, I'm limited by not having the greatest measuring tools and techniques.

If anyone else has measured the engine installation angle, I'm curious to hear what you came up with.

Thanks,
Chris

 

[jstorma]

My QA42A and 782 never had an issue. I did use the proper sheave for the 82 series that I purchased from a cub cadet dealer. Might have something to do with that......

 

[cmiller]

Thanks for the weigh-in, Jim. I'm also running the larger, 5/8" pulley, and feel the belt gives a good, long service lift (But I always have a spare on hand).

I'm taking this on as a fun little engineering exercise. Sort of the pursuit of the "perfect installation," without compromises for mass-production, etc. that IH/CCC engineers had to consider.

 

[cmiller]

During some holiday time off, I got into this a little deeper. But I ended up with more questions, instead of a happy resolution.

I removed some engine sheet-metal (but not the complete engine), just to get in closer with better measuring equipment. I determined that the transaxle and driveshaft are at approximately 4.0° to the frame, but the engine is only at 2.0°.

This leaves me with the uncomfortable realization that the front rubber/fiber joint must compensate for 2.0°. The engineer in me would like to think that the engine-driveshaft-transaxle alignment would have been designed at 0°, and that the joint just allows for some manufacturing tolerances, but there is no way that the engine-mounting plate is jogged at 4°.

I had the engine out of it years ago, and I know I messed with the spacers under the engine. But I'm sure that whatever I did, I used four of the SAME spacers. But maybe this is wrong? Should different height spacers be used?

Does anyone know what the "correct" engine installation is? Or have an explanation for why the engine-mounting plate is jogged the way it is? Maybe the 2° misalignment I measured is indeed "right", and it's some kind of mass-production compromise for using either the single- or twin-cylinder engine (?).

At the end of the day, it's been running fine as-is for years, but maybe it could still be made better. And I'd like to learn more about Cub Cadets as I go.

I'd appreciate anyone's thoughts and experiences.

thanks,
Chris

 

[mgonitzke]

All four spacers are the same.

There is probably some variation in each example of the engine mounting plate. I doubt they are all exactly two degrees. The transaxle tilt probably varies less since the mounting holes are pretty far apart from front to back.

 

[walls00000]

Thanks for this info! I'm happy to hear there are other 782 owners using a qa42a(b). I'm currently in the middle of installing the 5/8" pulley which ended up requiring a gear box rebuild. I'll keep this info in mind when it comes time to line up the pulleys.


Question for you about the PTO... Are you able to engage the snow thrower smoothly, or is it more like it turns on "freakin now!"? There is more on this question in my qa42a to b thread, but the short of it is that my gearbox has some broken teeth, which I suspect could be related to how my PTO engages abruptly.

 

[jstorma]

The 782 has an electric PTO clutch. Once that magnetic coil is energized; BAM, it's engaged. I'm sure the manuals state to run it wide open and engage the clutch, but I prefer more of an idle to do so. Too much of a shock. Never broke teeth. Someone may have had the blower full of snow or had something jammed in with the engine wide open and engaged the pto clutch. Or it just had a bad bearing.....

 

[mgonitzke]

Engage the PTO at idle or the slowest speed that won't kill the engine when it is engaged. The manual does NOT say to engage it at full throttle.

 

[jstorma]

I really have no idea what the manual says, never had one for a QA thrower. Now a days that seems typical to engage at full throttle.

 

[Doug Rusk]

Um no....

 

[digger]

I really have no idea what the manual says, never had one for a QA thrower. Now a days that seems typical to engage at full throttle.

http://www.ccmanuals.info/throwers.html

 

[jstorma]

Thanks Digger, always knew were to find them but I don't think I ever read the QA thrower manuals. Just says refer to the tractor manual. Tractor manual for the 782 does say to slow the throttle before engaging the PTO.

Thought maybe I read that in my newer MTD manual for a newer blower but just looked and it does say to slow it down. Maybe it was my Aunts old white or something I read to engage the PTO while wide open. Not sure where I got that from. Something I don't do and don't recommend, but I see all the people in my neighborhood engage and disengage their riders full throttle all the time.