Max IV, T20 or clutch issue?

[rickemd1]

ARGOJIM,

Ok so I got back home yesterday and shimmed the engine up to try an obtain the 1 1/2 inches of defelction on the belt, 3 large washers. I might have a little more than the inch and a half deflection at this point but I don't think that it matters now because I did try to drive it around my yard once and it seemed to perform as it should, turning left/right in both forward and reverse. Then again as I was trying to steer back to my garage, no steering in forward. I was able to drive it into my garage with some effort in reverse. It's almost as if the gearbox gets hot and starts slipping. IDK. Guess I need to split the case at this point.

[amphibious drew]

Wait a minute before you split it open. Do a band adjustment first and see if that works. You may just not be gripping enough on the drums to turn on pavement. Even a properly adjusted t-20 should not be turned from a dead stop on pavement. You should be driving forward or reverse a little bit. You may want to change your ATF as well and don't put any friction additive in it at first to see how she does.

[hydromike]

I don't think this has been brought up yet, but how hard are you pushing forward on the laterals when you're trying to steer it? I'm assuming you still have the spring-loaded laterals. Maybe there's enough spring and enough "grab" to the bands when it's cool to steer more easily. I'd do a band adjustment like Drew says and make sure you're pushing hard and pulling hard on the laterals to steer.

[ARGOJIM]

Both good points by Drew and Mike along with the woodruff key from msafi65 which is easily eliminated by pulling the clutch, if the spring has sprung it will also have less power and progress worse, if the bands are out of adjustment no matter how hard you push the c channels can only travel so far.

Did the machine operate properly before tear down? Let's start with a year or serial number, engine in it, driven clutch spring color , belt number you're running and what you have done so far, that should get us all up to speed.

It is possible it will have to come apart and may need some parts, or maybe it's something you or we are just not thinking. Didn't see any pics in the gallery so some of that in the trans area may also help.

Most of these other guys are more familiar with the t-20 than me, yet I do like to k.i.s.s. the little stuff before just ripping stuff apart.

[rickemd1]

Ok guys thanks for all the suggestions and advice. Rebuilding one of these without manuals has been a lot of fun

Here's some specifics about the machine; The serial number is 10375 and I think this makes it a '95 or '96. The engine is a Vanguard 16 HP I think from the numbers (303447). The driven clutch as you can see from the pictures is rust colored and when it rotates the 2 washers inside of it rotate with it as suggested by msafi65. The belt that I got from Richard is a MAX1092M2 and is 1 1/8" wide. I have had the frame and assorted control tubes etc blasted and powder coated. New Peer #50 and Tsubaki 530 chains, new drive sprockets and bearings all around.

I bought it sitting in a backyard full of water and not running. Of course all the chains were toast, drive sprockets were shark finned, T20 to rear axle chain on the left side was broken, all bearings FUBAR'd, and everything was rusted. I got the engine to run with fuel dumped in the carb but there was no reason to try and get it driving with the worn sprockets so I never drove this machine or any other like it before last Tuesday when I first posted my thread.

Prior to installing the T20 which is the only component that I didn't go through thoroughly, I drained about a gallon of gray goo from the gearbox. I flushed and filled and flushed and filled until pure red fluid came out, or about a gallon of ATF later. I added the ATF along with the diff treatment in the top vented hole until fluid came out of the bottom hole in the installed position. I also broke one of the diamond shifters in the process and replaced both of them with new shifters.

The sticks both have 4" inches of travel from the forward position (springs are installed). I have made no adjustments to the bands. The bottom plungers seem to be adjusted equally and the top plungers are about 1/8th of an inch off from one another. I didn't notice any difference regarding the level of effort to make the machine turn in one direction over another.

Since the original post I have adjusted the engine height with washers (yesterday) to acheive the 1 1/2 belt deflection on one side. I drove it yesterday and at about the 5 minute mark once again the steering started to fade. I was able to drive around on my grass and do some donuts beforehand, go forward and backward, right up until it quit steering or moving forward. I limped it back into my garage in reverse. I DID NOT try pushing the sticks forward or at least I don't recall doing that at anytime while driving forward.

Why does it steer fine for 5 minutes then suddenly fade? I'd bet that if I went outside now I could duplicate the ride I had yesterday and last Tuesday......for 5 minutes anyway.

Here are some assembly pictures.......T20.jpgframe and controls.jpgframe and controls front.jpgBody installed.jpg

And if anyone thinks that I need to adjust the T20 could you advise a tool other than the one Richard sells or MuddOx sells? I read where Mike said you didn't need to use tool to get the 5/16ths movement top and bottom. And I've looked at the PDF section of the T20 where it describes adjustment.

[msafi65]

4" of total travel front to rear is a bit tight. MaxIV should be 7". If the stick travel is correct the bands are adjusted properly. The symptoms are classic for the clutch. Spinning on the input shaft, they hold a bit then slip again. Try prying out on the driven clutch and see if it will move on the shaft. Normal is about .020" to 1/16" of end play. All the workshop manuals as such are available if not on this site I have electronic copies. The manuals are pretty basic but helpfull. The t20 rebuild section here is great info. Good luck

[ARGOJIM]

Hard to see but that spring looks sprung, get a better/closer pic of the clutch.

[rickemd1]

Since I have no idea what the clutch is supposed to look like I'll have to take the word of an expert. Now ask me about helicopters and I can tell you just about anything

Here are some pics I took tonight, I had to illuminate the clutch to get a decent pic. Whadya think?

I had to do some tinkering on the carb since apparently my fuel tank cleaning didn't quite get all the garbage out of the tank. Anyway, I had it running and tried to prove my point about the steering fading after a few minutes. Needless to say it did fade but I let it sit idle for a minute or so and tried it again and it worked, a little jerky it seemed to me but it steered regardless. So I got about 20 minutes of total ride time around my place on grass and clay, other than the apparent brief slippage it seemed to run fine.
driven 1.jpgdriven 2.jpg

[ARGOJIM]

Maybe I was seeing things, anyone else have an opinion on the spring?

[amphibious drew]

I think I would swap it out for a red one. It looks a little worn, and the 18 is a pretty small engine for a IV. Other than that, it looks ok. I'm still going with adjusting the bands.