SMB 4x4 front suspension issues

Jammyauto · 12-08-2007, 08:59 AM

I have allways been less than satisfied with the performace of the front suspension. The biggest complaint is the lack of front up travel and the very harsh bang that occurs frequently when the van bottoms out in front. I was under the van studying the supension the other day for possible improvements and I noticed that my van makes metal to metal contact when the suspension is compressed! THis is a major flaw. Here are the photos

This photo shows the top of the differential. The rusty area is where the diff is contacting the frame. It's rusty because the van has not been off-road in several months.

Here you see the bigger picture.

Here you can see the total amout of travel allowed! Not much at all.

Plans for improvement are
1. Cut back the area of the frame in the picture where it hits the front diff and reweld the frame.
2. Relocate the transmisson and stock engine oil filters further away from the front driveshaft to allow more travel and better clearance.
3. Install some bilistein hydralic bump stops instead of the rubber ones

scatter · 12-08-2007, 02:22 PM

Yeah Seth - My '07 looks the same. I've only hit mine once in this area (see my first flight post). The bump stops have stopped it all other times. That's not to say that there isn't lots of room for imporvement in this area. Just something I haven't got around to yet. This was the same problem I had on my previous Salem Kroger van. I had to do LOTS of cutting and welding to get more travel. It was even worse then the SMB is now. Let us know if you do anything to improve the travel.

mmocken · 12-08-2007, 03:23 PM

Have you contacted the installer? This is certainly not right, they should fix.

The frame is already cut back a lot...cutting anymore might give flex/crack problems...even if reinforced.

Jammyauto · 12-08-2007, 04:05 PM

First thing is that I'm not sure SMB would consider this a "problem". I'm pretty sure even the current 4x4 is like this. Secondly it's really not worth my time and $$$ to go back to SMB. I own a large automotive repair business and can do a better job on it myself anyway. A hour or so on the lift and I'm done vs. about a 15hr day plus 100.00 in fuel to get it to SMB for 5+ hours sitting in thier waiting room.

**daveb** · 12-08-2007, 09:04 PM

Seth, is your business close to Modesto?
Dave B

Jammyauto · 12-08-2007, 09:11 PM

No I'm in Santa Barbara. But I did not mention this because I'm interested in working on people's sportsmobiles. I am not. My business is general mechanical and collision repair, not custom work. The SMB is my hobby.

smb4me · 12-11-2007, 10:20 AM

i see where smb cut the frame/notched out the frame, did they install a mending plate (like above the notch) to reinforce the notched frame?

also, re: the quigley, anyone knows if they also have to cut the frame/notch the frame to fit their 4x4?

thank you

smb4me · 12-11-2007, 10:25 AM

i am quite surprised at the small vertical travel of the smb system,
anyone else have issues with the van bottoming out and hitting the bump stop HARD! damages?

can anyone comment the the amount of vertical travel on the
salem kroger?
quad van?
quigley?

thx

jage · 12-11-2007, 10:32 AM

I've noticed a klunk in my SMB 4x system and it looks like the bumpstop is slipping past the axle, but I haven't had time to figure out what is going on. Panion and I noticed that his custom 4x system has really close bumpstops as well, so it might be a byproduct of the van and the solid axle just not having enough clearance.

panion · 12-11-2007, 11:14 AM

Update on my bumpstops. They were in fact only allowing about an inch of travel. My builder put them there because he was matching the stock travel. We have since moved them up 1.5 inches without any issues. I used to feel them bump just driving around town, but haven't felt it since.

During the conversion we trimmed my crossmember, but also moved the front axle a couple inches forward to allow more room for the differential. This also gave clearance on the rear wheel well, no trimming necessary. Everything seems to be working.

An option we also considered was the hydraulic bump stops. They have some rated for 2000lbs each which could be mounted in place of the rubber stops. This would allow for a more progressive "hit" when bottoming out.