Breaking rear shock towers - likely suspect?
 

My brother in law has broken his rear shock tower the last two times out. Both times it snapped off right above the chassis rail mounts for it. (its a 3906) My diagnosis was that his shocks were possibly too stiff, however, I am second guessing myself as they really aren't as stiff as I have seen others drive.
Any other guesses?

I've seen lots of shock towers brake in the same place over on the numpty forum. Seems the shocks actually bottom out before the truck does, so the upward force of the suspension just sheers the towers off after a few landings; stiff springs would actually be the best solution believe it or not.

Try using 4 of the trinity XXX heavy blue springs, usually works a charm if you do much jumping. RPM towers would be better than stock, but then the bulks might suffer instead at the attachment point.

Well, he busted another rear shock tower yesterday. This is three for three now. His suspension is quite a bit stiffer than anything I ever ran on my Emaxx's, but I didnt do any jumping like we are now. Between this and the issue with his HV system, he's feeling quite frustrated at the moment, especially since the economy is hitting his business quite hard, and he doesnt have the funds to keep up with me (kinda makes me feel somewhat responsible).
I think I made the mistake of actually reducing his spring rate while we were doing the FLM conversion. Right now he is considering going to aluminum shock tower and bulks. I'm somewhat hesitant to have him invest that kind of money into the truck, since we havent really figured out the cause yet. I'd almost rather see him take that money and use it on a truggy conversion.

I broke a couple on my 3905 then switched to a RPM tower and didn't have any problems

personally i got
rpm toer
rpm bulk braces
rpm wear plates

havent had a problem since. the rpm towers will actually bend MUCH further and feel more "flimsy", but its those characteristics that keeps them from shattering like the TRX ones

If it is infact what Neil said, and the shocks are bottoming out before the truck is, I'd just get the FLM towers and call it a day. They have a ton of mounting positions so you can set the shocks in a hole where the truck will bottom out first.

When I was playing with it on the bench last night, with four wheels on the bench (and with the back two), the bottom of the truck does hit first. So the only scenario where the shocks bottom out first is in the event of a 1 wheel landing, or a sideways roll. I didnt notice him hitting those (at least not as badly as I was!).

rpm towers !

I broke a few towers as well, a new era 3 point cage solved that problem. It was more from landing on the roof on biiiig jumps. You may want to try out the rc raven springs, they are progressive springs and work great. Just use like 30wt in the shocks and when you have the shocks out install o'rings under the piston and at the bottom of the shaft. this will help keep them from bottoming out.

He ended up buying FLM bulks, and I think a FullForce RC shock tower, although I havent seen him since he said he ordered the stuff. He wanted to get FLM towers but Mike was out of stock - so I'm not certain which way he went. All he needs now is one of Sweetrideforme's bulkhead brace, and he'll be set. It's slowly turning into a pretty nice truck.

Tell him to be careful, I spent thousands on my Tmaxx and it seemed like the more I changed to worse the truck handled. I think back to when I first started bashing I could get that thing to grab some serious hang time, after all was said and done it was too heavy and it got sold. I even swapped in a picco .26maxx. It just wasnt nearly as fun even though I broke stuff everytime I went out when it was stock. Either that or the novelty wore off from chasing tunes.
I am now building a HCR Mutant Maxx BL it will be a lot more fun

Yeah, I agree. Its something I've been thinking about for a while now - as has he I'm sure - he comes home broken every time, and I rarely break anything now.
I'm probably going to try to get him into an RC8T, using Mikes conversion. He's trying to sell his million dollar condo right now, so when they finally get relocated, he should have some spare funds finally.