959 cracking away??

[tiger1]

Hi:

I have a 959 and the arms are developing some cracks. I have only driven the car for less than 10 minutes since I own it in 1997.

I notice that the cracks are on the arms only.

Questions:

(1) do you have the same problem?
(2) I notice there was no crack on the inner hinge pin pivot points on the gearbox side, do you notice the same?
(3) did you observe similar problems with other tamiya car, e.g. old hotshot??

Thanks

[shodog]

This is very common. For some reason the plastic is really brittle. I have a new built never ran 959 with a cracked knuckle. You could buy the $120 aluminum arms off ebay or spend nearly that much tracking down new oem parts. Boiling new parts may relieve mold stress in the parts

[tamiyadan]

.

[tiger1]

in other words, it is the combination of residue stress and thin ABS sections that result in this crack thingy.

I do notice that holes with thicker ABS/plastic faired better

MY 959 arms are almost all gone, the front knuckle was disasterous.... cracked at the ball join area.

Now I wish GPM made some metal parts for the 959

[tamiyadan]

.

[tiger1]

Is this plastic cracking problem unique to 959 or it is also common in other older tamiya cars??

[tamiyadan]

.

[EvolutionRevolution]

no every tamiya up till the early 1990s has this issue.

after 1992 tamiya went from ABS type plastic to poly type.

they also began to give more meat around screw mounts and they had a new plastic formula just for suspension arms.

The TA chassis was one of the first to go through this change, the TA01,TA02, etc. are very durable compared to earlier cars.

On the other hand, I've found that the TA01 and 02 arms tend to warp instead of cracking; they're too flexible and the mere weight of the car sitting on its wheels is enough to bend them diagonally over time...

[dsmith]

if your talkin R-parts on the celica gr.b...i have the same prob....

[2BornotB2]

good info, tamiyadan. appreciate it.

I picked up a used 959 last week, looks like the arms are already replaced. the seller said they were MRC arms, but I couldn't find anything about them.

[tiger1]

My solution is to stock up parts

[tamiyadan]

.

[2BornotB2]

Ok, they're not MRC arms then.. they're aluminum or something similar.

I'll snap a pic when I get home.

[DennisM]

I had broken one of the rear arms on my runner and the other had a bad crack - so I searched ebay and found only one set and that was priced a bit over the edge for a runner. Ended up bying TBG rear arms (their first run) and the carbon they´ve used, was so thin that it was impossible to assemble it in an usefull condition. Binned the TBG arms and ended up using a day in the shed with axe, hacksaw and grey plastic. It´s not the prettiest but now I´ve got rear arms that holds.

The 959 is a mean rally machine with it´s Technigold motor.

[tiger1]

did you notice any crack on the pivot point over the gearbox side??