Measuring ride height at front axle

[tmitchell]

The Spartan literature states to measure from the bottom of the frame rail.
When I measure at the location by the front axle, there is part of the IFS assy. attached to the rail(which makes it like a double thickness of frame rail). Do I measure down from that piece (or am I suppose to go far enough forward or aft of the axle area so my measurement is taken from actual bottom of the frame rail?
Tom

[tmitchell]

The Spartan literature states to measure from the bottom of the frame rail.
When I measure at the location by the front axle, there is part of the IFS assy. attached to the rail(which makes it like a double thickness of frame rail). Do I measure down from that piece (or am I suppose to go far enough forward or aft of the axle area so my measurement is taken from actual bottom of the frame rail?
Tom

[GaryKD]

My coach's rear measurement is taken the same way. I go from the bottom of the frame rail. I checked this after Spartan adjusted the ride height. It was exactly where the spec said it should be.

[Escaper1]

what is the ride height suppose to be in the front and rear

[GaryKD]

For my Mountain Master chassis the ride height is:
Front (Granning IFS 1260 front end) = 16.36" measuring the distance between the shock centers of the shock mounts.

Rear (W/240AR Rear Suspension) = 8.25" measuring from the bottom of the chassis frame rail to center of the axle housing.

[quikduk]

My '98 Gulfstream has an AP-GT chassis which Spartan says should have a 8.25" RH measured as you describe. I first went off the 16.125" measurement from center of shock pin to pin but this is incorrect for my chassis. The front is an I-beam and this measurement taken from the bottom of the frame rail to the top of the axle spring pad should be 10.25".

I guess I have to go and re-measure/adjust...again. I am hoping this will silence the angry bees I feel in the accelerator pedal and steering wheel, otherwise it is on to the driveshaft u-joints and possibly tire re-balancing.

[quikduk]

I need to clarify my ride height adjustments. I spoke at length with Spartan and this is what I have come up with.

Based on my chassis being a AP-GT (Alpine GT) and even though I have the same rear W240AR rear diff., my measurements are taken (as on the MM chassis) from the bottom of the LOWER frame rail that the suspension attaches to.

With this in mind, the rear measurement is taken from the bottom of this LOWER frame rail to the centerline of the differential. The weld on the axle tube is close enough for this centerline measurement according to Spartan. This measurement for the AP-GT is 6.25" (8.25" for the MM).

The front measurement is taken from the bottom of the same/similar LOWER frame rail to the TOP of the I-beam axle spring pad (the cast flat surface where the leaf spring rests). This measurement is 9.50" (10.25 for the MM).

There are subtle but substantial (is this an oxymoron or am I...)differences between other axle configurations and chassis models so be sure to give Spartan the last 6 digits of your VIN # and have them verify what your particular set-up has.

[quikduk]

UPDATE! I measured and adjusted the ride height as accurately as possible given I had to "shim" the wheels to get the coach close to level on my driveway.

I followed the measurements that I posted previously and it has made a HUGE difference. The vibration through the accelerator pedal and steering wheel is gone and the coach seems to ride better. I still need to get the tire balance and alignment checked to be sure but WOW!

Now I just have to replace the u-joints etc. etc.

[GaryKD]

quikduk,
Congratulations ride height is a difficult adjustment to make.

[quikduk]

Thanks Gary.

I still need to fine tune the levelers and I may need taller vertical rods so that I can have a little poking out the top of the rubber grommet. I need to find a perfectly level (in both directions) pad to adjust these so I may have to bribe the BIL with beer so I can have him move his MH and use his shop.

Ken