Problems with OS 18TM

[Shane1041]

I am having some problems with a OS 18TM in a revo.....I was running last weekend and the One way bearing went out so when I tore it down I found that the clutch bell bearing ( Outer) and the e clip was MIA ....So I replaced the one way with a used one way and a used outer bearing and a used E clip for the clutch bell , Well I ran it agian this weekend and guess what ....the one way started slipping and I lost the e Clip and the outer bearing on the clutch bell ........So what gives ? Is the front and rear bearing shot causing the destruction of the bearings on both end of the motor? ...I am just about tempted to replace this motor and do a complete rebuild on this motor ......But I figured with the wealth of knowledge on this board I might be able to find a way to fix it without replacing bearings ....thanks


Could it possibly be the one way bearings that is causing enough vibration to lose the e clip off of the clutch bell?

 

[olds97_lss]

e-clips suck. Use a screw with a washer and a few shims on the end of the crank shaft instead of the e-clip slot. This will guarantee a more solid setup. I always had problems using the e-clip on my maxx, so I didn't even bother trying one on my revo. At least after I installed the 18TM.

Over time, one ways go out and/or need cleaned. Check the shaft the one way rides on. If it's rough, it will eat up a new one way pretty quickly.

Normally, about once a gallon or so, I pull the engine, pull the OWB (one way) and soak it in DA for a few minutes. Then I work a paper towel through the OWB and wet it with more DA and spin the OWB on the paper towel in both directions a few times. I do this until the paper towel comes out clean. Then I lube the OWB with light oil, normally 3-in-1.

I do this on any engine, not just the 18TM in my revo. I've gotten as much as 10 gallons through my one way on my OS 21 RG in my savage. You just have to be mildly religious about maintenance and things tend to last a lot longer.

 

[Shane1041]

Thanks for the reply Olds , So what should I use as shims ? you wouldnt know the size of the screw I would need would you?

 

[Monkey Wrench]

Personally, I've yet to lose an E-clip. Before I put it back on, I gently squeeze it with a pair of pliers to make sure I get a good "snap" when I clip it back on. Have yet to lose one.

As for the OWB's, if there is an Achilles heel to the TM, IMO, it's their OWB's. I went through a fair number before I converted to a bump start, but what Olds suggests is the way to go. For the life of me, I can't figure out why that mill eats OWB's, except that the EZ start or rotostart (whatever you are using) simply put out too much torque for the bearing to handle over a period of time. It's a guess, but it's all I can figure.

 

[jetmechG550]

For the screw a 3mm x say 8mm would work, you may even be able to go down to a 6mm length. I've only lost one e-clip but I disitegrated a set of clutchbell bearings. I usually pull and clean or replace cb bearings about every gallon or so.
I myself have never launched a OWB but then again, one of the first things I did was convert to bumpstart and loose the OWB.

 

[olds97_lss]

I'm on gallon #2 on my 18TM with the original OWB I started with. It hasn't started slipping or showing signs of wear yet. I just had it apart two days ago for cleaning and maintenance. Maybe your just hard on things MW .

Like I said, I had issues with the clip on my t-maxx, but I believe it was because the engine would move forward on "not so nice" landings and ram it into the trans case. Which in turn would peel off the e-clip. I've used a 3mm button head with a washer on every engine since.

For shims, I normally use traxxas teflon washers. I think they are 5mm. You can normally fit one on the shaft then be able to tighten down the screw in the crank shaft without binding it. You may have to move the flywheel...

EDIT: I just had a thought, I use a pullstart, not the EZ-start... That may be why mine is lasting. I use a pullstart due to the fact that I don't like to depend on a battery to start my truck and I don't want to carry it with me all day. I also like to feel what the engine is doing as I start it. If it's hydro locked, I know. And I can set it at BDC when I'm done for cool down easier. Besides, with the 18TM, it almost always starts on the 1st or second pull. So did my 2.5R for that matter...

 

[bustedgears]

Shane, are you using a traxxas owb? Are you always replacing them with NEW ones, or just ones that you have?

 

[Mr T-Maxx]

The issue is that the shaft in the rear of the OS is about 3mm shorter than the shaft in the rear of the TRX engine. The OWB can hang off the end of the shaft, lock up and then spin your roto start to oblivion The rort-starts aren't design to spin at 20,000+ RPM.

Last race I was at three different racers days ended due to this issue (myself included).

And as Olds mentioned, check the shaft, they get ate up when this above happens.



Mr T

 

[Shane1041]

Well I am thinking ....I replaced the bad OWB with another bad one lol .....I put a fresh ( New) OWB in and everything seems alright .....I havent spun the Eclip off of the clutch bell either..

I need to find a good reason to get a EB Mod OS 18TM.....I broke one in for a friend today and I must say it is real smooth engine and seems to have a lil more power through out the RPM's ......I am impressed but I dont know if I am impressed enough to spend the extra loot