Hitech 5955 servo issues

[scoutdawg]

I have a hs-5955tg servo that's on my wreckluse, it will not hardly turn my tires when not moving. I have used this servo before and it did fine. It's chassis mounted and everything seems tight but this thing won't turn for crap. Any insight will be appreciated.

[Calderwood]

5955s are getting up there in age. You may just be seeing the effects of a worn out motor combined with the extra stress of a cms setup.

[JokersWild]

If it works fine axle mounted and cms is the issue..... May be bad steering geometry. Post up pics head on with steering.

[scoutdawg]

Here is a couple of pics, after playing with it more and really paying attention I am seeing alot of body rise and spring unload when turning right mainly.
Any thought on a remedy? Am I gonna need to put a panhard bar on here even though its a 4 link on the front?

[Ryan87zuk]

4 link and cms don't play well together. The links follow an up and down motion only, and the steering link wants the axle to swing side to side. Take off the the tie rod at the servo horn, hold it in position where it normally is bolted and move the suspension up and down. See how the tie rod would be trying to pull on the servo horn? When you put a panhard rod on, and take one of the upper links off, the axle will travel with the tie rod side to side (slightly). Just make sure that the panhard rod and the steering tie rod are perfectly parallel to each other. If they are not, you will still get bump steer. This could very well be your "weak" steering issue. Hope this helps.

[Calderwood]

Originally Posted by Ryan87zuk

4 link and cms don't play well together. The links follow an up and down motion only, and the steering link wants the axle to swing side to side. Take off the the tie rod at the servo horn, hold it in position where it normally is bolted and move the suspension up and down. See how the tie rod would be trying to pull on the servo horn? When you put a panhard rod on, and take one of the upper links off, the axle will travel with the tie rod side to side (slightly). Just make sure that the panhard rod and the steering tie rod are perfectly parallel to each other. If they are not, you will still get bump steer. This could very well be your "weak" steering issue. Hope this helps.

Saying 4 link is to general. The triangulated 4 link will induce bump steer when used with a cms like you said but a parallel 4 link using a pan hard bar would not.

[scoutdawg]

This is a single triangulated 4 link (just the uppers are), so what you are saying is make it a 3 link with a panhard and it will make a huge difference? I am all for trying anything to make it work better
Thanks for all the help guys

[Ryan87zuk]

Nigels world : very well said. Thanks for the correction.

[scoutdawg]

So I fixed the raising chassis issue by putting a panhard bar on it and it actually crawls very well with it but for some reason when on rock it just doesnt want to turn left unless your moving. It's very responsive and fast when not on the rocks. Is there anything else it may be? Thanks for all the help so far

[JokersWild]

Is the rig rolling or rocking when trying to turn that way? Also have a pic from the side with wheels off? May be mis aligned pressures from servo to knuckle. Also may just be like said above, the test of times on the servo.

[scoutdawg]

The rig rolling and rocking has stopped after putting the panhard bar on it, I can take a pic of the side with no wheels in a little bit but the drag link from the servo horn to the knuckle is parallel to the tie rod.