Spectrum 3T Climax drive clearances

[oldcoastie]

My newly acquired 3T Climax runs, but hesitates each rotation of the drive shaft. The problem is that two of the cylinder-shaped "universal joint" housings, located where the drive shaft connects to the first and third trucks, rub against the u-shaped keeper that stretches across the trucks under the universal. (On the last page of the exploded parts diagram, Front Truck, PartOAJO6 is rubbing against Part H828X-00v02). The universal joint is not a perfectly round part, and the protruding side rubs against the U of the truck part every revolution. This makes the Climax hesitate and strain each shaft revolution as it moves down the track. At low powers, it doesn't move.

!. has anyone else had this problem, and , if so, how did they fix it?
2. can the truck cross member (which has the U in it) be removed and repositioned or replaced or sanded thinner and replaced?

Any suggestions will help. Thanks, and pardon my ignorance of correct terminology. 

[WoundedBear]

To me it sounds like the pins of parts 0AJ06 and it's mating yoke, 0AK02, aren't positioned properly in the holes of the surrounding o-ring, H819X-A0D01.

Verify that you have four pins sticking through the four holes and that the joint assembly is round. If the pins aren't through the holes properly, you will get an oval shaped joint. Make sure none of the yokes have split as well. This would give an ovoid joint also. Also check that the o-ring isn't torn.

There should never be a need to modify, clearance or reshape any part of the truck itself. As a rule, the Climax models run as smooth as a Rolex.


Sid

[oldcoastie]

Good suggestions, Sid. I'll need to do further dis-assembling to find out the answer whether the pins are protruding. Will have a look today and get back to you.  Thanks. And I'll try to take close-up photos of what I find.

[oldcoastie]

Here's a photo of one of the rubbing universals. It isn't unseated pins that are rubbing. The "pins" seem to be a molded part of the plastic universal. The universal seems to be out-of-round.  If I knew how to remove the truck from around the wheels, I could see better and measure how far out of round they are.

Can you tell me how to remove the trucks? Do I just pull them off, and then unscrew the truck frames?

I'm having trouble uploading the photo. It's only 64K but the Board is telling me the upload folder is full.

Thoughts on removing the truck frame? Or getting the photo uploaded?

[Len]

You can't upload photos directly to the forums. You have to upload them to something like 'Photobucket', then copy the image location into the forum using 'img' tags.

Len

[WoundedBear]

The trucks come off with a firm tug. Warning.....the trucks are a bugger to get back together....proceed with caution if you dismantle them.

Sid

[oldcoastie]

OK. Let's see if this img works.  If it doesn't, I have a link to the picture in OneDrive. Let me know if the img works:

<img src="https://ai8gyq.dm2304.livefilestore.com/y3pEa32jP7Vg0dw3sbQGNZApvGX2Bp7XBRKbW3_ToSCaswBKrJi43JPecAJ-76k2T5gBmlH5zRu2fcyztEOQUQswzQlcJqRsbmTtITgILDQip6drAYimo2wUL6cDmx8YT9ETGwW6eRUQiZU7Coz4DiheA/Climax%2bDrive.jpg" width="1000px">

oldcoastie

[oldcoastie]

Trying to download picture again, this time using Photobucket and after reading directions in Bachmann forum.



I think that worked.  Thanks for the photo-insert help. (I do have skills!).

I hope this shows the odd shaped universal clearly. I really don't want to remove the trucks.  Thoughts?

[Len]

My eyes aren't what they used to be, but the universal doesn't look 'out of round' to me.It looks more like the shaft isn't lined up correctly, so it's pushing the universal to one side and causing the rubbing. Is whatever's on the other end of the shaft actually in the proper position??

Len

[oldcoastie]

In the previous picture, I have a skewer I have shaped to a square cross-section so I can insert it into the square drive shaft tube and turn it easily to see where it hangs up. (One of the other drives hangs up as well.) It's partly a matter of the in-and-out slop on the shaft on the truck-side of the drive shaft. This problem increases with this truck because I have removed the bottom plate which holds the drive shaft and bevel gear securely in place.

Here's another picture of the same shaft and universal.


The shaft and universal are all plastic, and the "hole" in the square drive shaft next to the universal I believe allows the flexible ball joint to snap into the universal. I must admit that sometimes the universal looks obviously oval, but others it looks OK.  The light is difficult and like yours, the eyes are not young. I used a finger LED light to illuminate these shots in addition to the flash.

So do I have any options short of taking the truck off?

[Len]

Wrap a piece of 1,200 grit emery paper around the universal and move it back and forth until enough material is removed to stop the rubbing. Or flip it around and remove the high spot from the universal. Or possibly do both.

Len

[oldcoastie]

Yeah, I think that may be the (1) easiest; (2) fastest; and (3) least risky way of dealing with the problem.  It can't be more than a few thou that need to come off, and on the positive side, anything off will help. I'll report back in a day or two the results (Maybe even figure out how to post a short video of the results, good or bad.)

So thanks you guys, Sid and Len.

[oldcoastie]

Problem solved. Turns out there was no hole for one pin of the universal swivel inside the housing. As a result, the plastic-rubber housing was out of round because there was no hole for the pin to seat into on one side.



So I drilled a hole in the universal housing like this:



Reassembled the truck and the out-of-round universal was gone.



It sure took some time to figure it out. There was a "dimple" hole showing on the outside of the housing, but you couldn't see it wasn't a through hole until you took it further apart. Frustrating, but satisfying to be fixed properly.

Thanks again to Sid and Len for support and guidance.

[Len]

Hmmmm...Now that was unexpected.

Len

[WoundedBear]

Hmmmm...Now that was unexpected.

Len

Not really....I had that pegged as the problem in my first reply where I said "check you got 4 pins in 4 holes and a round joint".

Sid