Traxxas Slash suspension sag

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Justinc

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Hey everyone, I'm new to the hobby and have a Slash 4x4. The truck is only a couple of months old and I have just noticed that the rear suspension is sagging and will not rebound to where it use to be. It bottoms out very easily. I've sent this pic and a video to Traxxas via chat, they were rude and said its normal and that I was trying to create an issue which I am not. The springs have never been changed so shouldn't the height remain the same? Thanks!
 

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shock springs could be worn. most likely its the shock shafts themselves. the poor geometry that is in many traxxas Leeds to bent shock shafts.. rebuild shocks with a few new parts. new springs shock rebuild kit.. check shock shafts on a flat surface...
 
Could be your shock fluid has leaked out or you may just need to empty and refill them with some thicker weight shock oil. You can also try stiffer springs or pre-load clips to stiffen up the existing springs a bit. First thing though is check your shock oil and make sure its full.
 
It is hard to say what is the culprit without seeing the actual chassis. It could be a combination of things. I am not familiar with this chassis, but based on other cars I have owned it could be the A-arms are bowed/sagging. Take pics of the chassis from the rear, top, etc.
 
Could be your shock fluid has leaked out or you may just need to empty and refill them with some thicker weight shock oil. You can also try stiffer springs or pre-load clips to stiffen up the existing springs a bit. First thing though is check your shock oil and make sure its full.
Thats where I'm leaning. Alot of people suggest aluminum shock caps to stop leaking.
 
When I first bought my Stampede 4x4 I kept blowing the cap off of the rear shocks and tried everything to keep them from doing so.
I bought aluminum caps and never had a problem again. Granted that doesn't explain your issue but if you are going to rebuild yours shocks then I definitely recommend them.
 
so shock oil now holds the shock up? how... rebuild shocks .test installed shafts also.. replace springs.
 
so shock oil now holds the shock up? how... rebuild shocks .test installed shafts also.. replace springs.
While its true that the shock oil doesn't hold the RC up the OP also mentioned that his kit is bottoming out very easily which would be an indicator of low shock oil so I dont know why you're giving everyone attitude about mentioning rebuilding the shock and making sure theres proper amount of oil in it. No one is really focusing on the springs because theyre only a couple months old and its doubtful that the OP wore of his shock springs in that short amount of time. Replacing shock springs that new would only be something I would try once I had exhausted all other possibilities first since its not a likely candidate as the failure point. Having said that I did mention the springs and pre-load clips just to cover all the bases and tuned pipe even commented that the shock caps/ shock oil doesn't address the issue of suspension sag. Did you even bother to read the whole thread or did you just decide to jump in a flame everybody for no reason?
 
Hey everyone, I'm new to the hobby and have a Slash 4x4. The truck is only a couple of months old and I have just noticed that the rear suspension is sagging and will not rebound to where it use to be. It bottoms out very easily. I've sent this pic and a video to Traxxas via chat, they were rude and said its normal and that I was trying to create an issue which I am not. The springs have never been changed so shouldn't the height remain the same? Thanks!
Ok so with all that crap said above LOL. Unless you are racing your slash. In a couple 2-3 months NO WAY your shock springs are worn out. The shocks are not supposed to rebound all the way out either by the way. They are only supposed to rebound 1/2 to 2/3 back from all the way in against the bottom seal cap. How and where do you drive it? Racing buddies , jumps, bash the hell out of it. Dirt field , sandy place. In Dry and dusty areas That would help. Your o-rings and seals will wear out on your shock before anything else. And your oil will leak out. If that happened your rear would be very bouncy. As it would only be on springs. If you driven in dirty dusty area. Did you check to see if your hing pins are bent? That wouldn't allow for rebound. Pull your shock off and see if your A arms drop when you lift the rear. If the don't fall freely and fast then you might have bent hinge pin. Or you landed wrong off jump and bent a shaft. If not to either of those. Check your oil and You can try more per-load for the shock. The little black round clips. Add a few. And check the shock. If none of the works then I would go ahead and try to rebuild them at that point
Here is a break down on how to rebuild or refill your shock.

"How to Rebuild Ultra Shocks | Traxxas" https://m.traxxas.com/news/how-to-rebuild-ultra-shocks
 
Ok guys so I removed the shocks and looked at the oil. I have the aluminum shock caps installed and I noticed one was leaking slightly. The leaking one was down a little but the other is just about top full. I am picking up some 50wt tomorrow and will also try some more preload. I should also mention that I have the Tekno M6 driveshafts front and rear but nothing appears to be binding in the suspension. I have attached a pic of my available ground clearance using a spur gear as a reference. This slash is super low lol.
 

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If oil is good, I would add a preload spacer or heavy oil as you mentioned.
 
Ok guys so I removed the shocks and looked at the oil. I have the aluminum shock caps installed and I noticed one was leaking slightly. The leaking one was down a little but the other is just about top full. I am picking up some 50wt tomorrow and will also try some more preload. I should also mention that I have the Tekno M6 driveshafts front and rear but nothing appears to be binding in the suspension. I have attached a pic of my available ground clearance using a spur gear as a reference. This slash is super low lol.
I wouldn't go 50wt. In a Slash I would say 35 40 tops. You won't have any damping. They will be very stiff. I use 40wt in my Tmaxx. Did you check yout A arm drop with shock off? Does it fall freely? Drive shats won't have anything to do with the shocks rebound. Check your hinge pins while shock are off in you a Arms bottom one inner bottom ones.
If oil is good, I would add a preload spacer or heavy oil as you mentioned.
The heavy oil will only slow the shock travel down. Not help with the rebound.
Wait it looks like you already have the biggest preload clip for the shock already. So you go a lot of preload on those little shock already. There has to be something bent. The arms in the pic don't even look level. Look as if the are till compressed from landing.
 
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I wouldn't go 50wt. In a Slash I would say 35 40 tops. You won't have any damping. They will be very stiff. I use 40wt in my Tmaxx. Did you check yout A arm drop with shock off? Does it fall freely? Drive shats won't have anything to do with the shocks rebound. Check your hinge pins while shock are off in you a Arms bottom one inner bottom ones.

The heavy oil will only slow the shock travel down. Not help with the rebound.
Wait it looks like you already have the biggest preload clip for the shock already. So you go a lot of preload on those little shock already. There has to be something bent. The arms in the pic don't even look level. Look as if the are till
 
Hey did you get a second to read my first response bud? Give it a read.
 
Yes the biggest preload clip came already installed on it. I took the whole suspension apart earlier and made sure nothing was bent or binding. To me, it seems as if the car is too heavy for the springs. This is very little rebound. This was a brushed slash and I've added motor fans/heating, esc fan, tekno bigbone center shaft, tekno front and rear driveshafts and gorilla taped the body. So she is definitely heavier than stock.
 
Hey did you get a second to read my first response bud? Give it a read
Yes the biggest preload clip came already installed on it. I took the whole suspension apart earlier and made sure nothing was bent or binding. To me, it seems as if the car is too heavy for the springs. This is very little rebound. This was a brushed slash and I've added motor fans/heating, esc fan, tekno bigbone center shaft, tekno front and rear driveshafts and gorilla taped the body. So she is definitely heavier than stock.
Well you should have added all that to the first post. LOL. That would have helped. So your truck is now to heavy for those stock springs for rebounding .So you will need stiffer springs not thicker oil bud. The heavier oil wt. Will only help with compression not rebound. You can go 50wt with all that stuff added. Might help with the chassis slap. but will definitely need stiffer springs as well to help with rebound of the shock. To get the truck back to a good ride hight. But the link I sent you will show you the proper way to rebuild/fill your shocks. And how to make sure you don't have any air bubbles in them as well.
 
Hey did you get a second to read my first response bud? Give it a read

Well you should have added all that to the first post. LOL. That would have helped. So your truck is now to heavy for those stock springs for rebounding .So you will need stiffer springs not thicker oil bud. The heavier oil wt. Will only help with compression not rebound. You can go 50wt with all that stuff added. Might help with the chassis slap. but will definitely need stiffer springs as well to help with rebound of the shock. To get the truck back to a good ride hight. But the link I sent you will show you the proper way to rebuild/fill your shocks. And how to make sure you don't have any air bubbles in them as well.
Thanks for all the help. Do u think I should invest in gtx or proline shocks instead?
 
Thanks for all the help. Do u think I should invest in gtx or proline shocks instead?
Read this you will have a better understanding about you shocks and how they work. That is up to you. Either one is better. As there are aluminum bodies. And better shafts. As to the plastic bodies and cheap metal shafts of the stock shocks. But you can probably fix the problem of chassis slap and rebound with with thick oil and stiffer springs. At this point you will have to play around with both of those to get what your looking for. But read below. It will help you understand the RC shock and how they work

"RC Suspension Tuning Guide: Part 3 | Traxxas" https://m.traxxas.com/news/suspension-tuning-guide-part2
 
Do u think I should invest in gtx or proline shocks instead?
Traxxas GTR shocks are pretty good. I have them on my Slash 4x4, paired them with TLR 10SCTE springs and they have been doing pretty well on the truck. Proline shocks are also good from what I've heard, but their prices never really appealed to me.
 
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