ATC 90 questions

[dz]

Hello. I am getting an 1974 ATC 90. Probably going to pick it up saturday. The problem is that the guy is telling me that 1st gear does not work, but the others do. He is also telling me that it has the hi-low transmission. I have never owned an ATC before (owned trikes before), so could somebody please explain the hi-low transmission to me? If it is a hi-low transmission, shouldn't it only have 2 speeds, hi and low, or does it have 3 speeds but hi and low ranges? Also, does anybody know what might be wrong with 1st gear? Thanks and I would greatly appreciate any help.

[plkmonster2]

the older 90's are prone to the first gear stripping. You will have to replace the two gears that run it. High and low mean that the transmission has a high gear ratio, faster, but less accelration, and a low range, more accel, but less speed. It would mean a total of 8 gears, all 4 gears have two ranges on the tranfer case. This is much like manual 4x4's. The first gear is very easy to strip out if you use it too much, or you "pop" it into gear. Believe me, if you are too heavy for the machine, you will be replacing them often. I dont know what the fault is, but those years had some defect. If you are over 120 lbs, i wouldn't get a 90, unless it is for a child. ;)

[greenhuman]

Plkmonster2 is correct on everything except the first gear blowing all the time. The 90's have a very good gearbox with no known faults. I have had every size 90 motor from 180cc alky burners to 310cc with XL175 head and cylinder grafted on with no gearbox problems at all.
The only time you would see a broken gearbox is clutch starting after you've broken a rope or a chain derail at high speed and locked up the box.

[dz]

Well, I just picked it up today. It runs well. First gear does not work at all, and when in the higher gears they sometimes slip out and I can hear almost like a tumbling sound inside of the gear box. What else could be the problem and how much does it entail to take the cover off and change some of the gears? Thanks.

[plkmonster2]

i guess it could be from push starting :rolleyes: lol, or maybe revving it up and popping the gear. :-D

[dz]

The pull starter is still there, and it works. I don't think it was push started. How hard is it to tear the right side cover off and then tear apart the transmission?

[ATC340PVR]

You need to split the cases to get at the transmission

[bigred110]

You can pop off the transfer cover box on the side and check to see if the gears are good. It's were you can you can change if from high to low gear or either way around.