dicktill
Senior Member
Originally Posted by Rulebreaker
Booster, thanks for this wealth of information! Very much appreciated!
Front:
I'd be interested in your opinion on the merits of the Moog 18004 vs the Husky SC20470. It seems the 18004 is constant rate while the SC20470 is progressive? Might this translate into smoother ride on the SC20470 at the expense of reduced vehicle height versus the 18004? The Husky seems to be listed as a constant rate where I looked and a cross for Moog 81006 which is shorter than the 81004 most have used in post 2002 models. You would have same rate but less length and lift. I don't like variable rate for constant heavy loads because the softer coils are over worked.
If I decide to seek additional height later using 3" spindles as some have done, would both of these springs likely still work for me? Some have done OK with them and some have not. Personally I don't like knuckle lifts because they mess up the suspension and steering geometry, and I can always feel it. I am pretty particular in regards to steering, others not so much.
Rear:
Is it just the adjust-ability of airbags that you prefer over using additional springs? For me, vehicle loading is pretty constant and we don't tow anything, so no trailer tongue weight to consider. (I'm just trying to rationalize the added cost and complexity vs. the benefits.) As for type of airbag; it seems some have used Firestone, while others chose Air Lift. Integral bump stops within seems to be a worthwhile feature. Is there a particular make and model of airbag that you recommend? Adjustability is nice, but most have found they ride a bit better also, but some claim worse. We are currently running ours the stock springs with the overload leafs removed. It really improved the ride, but there is only one other van doing the same and was just recently done, so not ready to say for sure good to go yet. With the overload out, we need to use bags with built in bump stops in case a bag pops as the bags sit where the original bumps were on the axle. Firestone bags would not need the internal because they are not mounted on the axle. I prefer the Airlift as they are larger diameter so less pressure plus they put the load directly on the axle tubes rather than on the lower spring bottom plate. Neither brand is bad IMO.
Shocks:
Bilstein B6-24-187435 front and B6-24-221948 for the rear seem to be the shocks of choice. Your thoughts? I gather if I decide to pursue 3" spindles for additional lift later, these B6 shocks might be too short? True? Knuckle lifts usually leave the lower control arm in the stock location and would use the same shocks, AFAIK. If you go more than about 3" up with springs, you will need longer shocks most likely.
Rear Sway Bar:
Vehicle has an under-hood generator (rather than under vehicle) so a Hellwig sway bar should work.
Overweight Vehicle, Wheels, Tires, etc.
Yep, vehicle is definitely overweight by about 3%, so I'll look at what I can do to lighten it. I do have aluminum wheels, so the offset issue you mentioned applies. Tires still have lots of tread, but when they're due for replacement I'll definitely look at upgrading wheels and tires to provide more load capacity.
As for front tire pressure; it seems 50psi is what's recommended on the vehicle nameplate as well as on Bridgestone load tables at the 2,050lb load per tire I have. I understand 210s tend to be lighter in the front than 190s due to the overhanging weight at the rear. Is the move to 65psi in the front, (presumably to improve handling and ride quality and to reduced heating and rolling resistance) likely to cause uneven/excessive tread wear in the center of tires over time due to crowning? It appears the plates are the stock ones or copies of the same pressures, and would be inteneded to cover an empty or full van without changing pressure. The 50psi squeeks in capacity at full load and would ride decently at low load, so a compromise on both ends. The 65psi is what most have found to be the best mix of steering response and tracking vs ride quality. Some like less, a few like a bit more. The tires will run cooler and wear the edges less at 65psi in most cases. Be aware you may have more weight on one side than the other by a couple of hundred pounds so splitting an axle weight can be a bit off.
Recently I measured ground clearance on my rig to the fresh water tank drain valve and it was a measly 4-3/8", so I'm definitely looking forward to gaining some additional clearance from these mods. Very believable at your weight. Probably low point right at the fragile tank valves and macerator, like we had.
Cheers,
Brian
I have the other van that is modified similar to Booster's: same airbags & overload springs removed, and both have large rear swaybars, albeit slightly different. Main difference is that I have aluminum spacers (replacing the overload leaf) on both sides, while Jim has only one side done. I may have to copy him on that too as I have a (small) constant pull to the right. So far we have about 750 miles on it and the handling and ride are great! (at least for a Chevy van, far better than stock methinks)
Regards, Dick
