Front End Skips On Humps With New Bilstein Shocks and King Springs

[RedThing Lurker Find all posts View Profile Close RedThing]

Finally fitted some Bilstein BE5-A713 and BE5-A712 shocks and medium raised King Springs on the 120 Prado for a 2" lift.

Ride seems good but one thing that is a surprise and not so good, is when you take it over a speed hump slow or fast the front wheels seem to skip/hop/jump as they come down like the shocks are not extending far enough or something. Has anyone had any experiences like this?

Going of many forums most people seems to use the BE5-A713 and BE5-A712 models so I thought it should be fine.

[GreenVX Junior Member Find all posts View Profile Close GreenVX]

Hi RedThing,
your not alone here mate. Bilstein have designed their shocks to handle as well as possible across all terrains and as such some of their on-road comfort gets sacrificed for longevity and performance.
Its not entirely their fault as they work as a coilover with your springs and they too contribute some to your rebound rates. Coilovers tend to hop or rebound more harshly if there isnt sufficient weight over the front wheelbase to counter the springs rebound rate.

The Bilsteins on my 90 series do the same thing on speed bumps at 10+ km/h, also tyre pressure also plays a part here too.
So if you find they are too rough the only solution is to slow right down on the humps and maybe drop 3 or 4 psi out of your front tyres.

Hope this helps you some mate. GVX

[RedThing Lurker Find all posts View Profile Close RedThing]

Thanks for the GreenVX. Interesting.

It was surprising, as with the old standard suspension setup it used to take a speed hump pretty smooth. I would have expected a aftermarket Bilstein setup would have been better.

So you don't think its got anything to do with the length of the struts? It kind of feels like the struts are fully extending maybe and so not allowing the wheels to drop down the other side of the speed hump fully.

Does Bilstein make an extended strut I wonder?

[stevensr34 Senior Member Find all posts View Profile Close stevensr34]

I have your same setup - the shock length is fine - I have had all four wheels off the ground at 90km/h (near Finke - mis-judging a big hump), and I can assure you that even then, the shocks did not fully extend...

[Guest Close Guest]

Can you provide some measurements?
1. Bottom of rim to wheel arch
2. jack up so the front wheel is at full droop and do the same measurement.

[fourbyphil Senior Member Find all posts View Profile Close fourbyphil]

how much weight do you have over the front, ie dual batts, winch, bullbar etc.?

I noticed with mine they felt a bit like what you have described until I had put all the extra items on the car then they settled down a bit. Mine are the medium old man emu 884's.
Cheers
Phil

[RedThing Lurker Find all posts View Profile Close RedThing]

amts: I will get some measurements going and post soon.

fourbyphil: At the moment all I have on the front end is a dual battery setup. so no weight really.

[Peterpilot Avid PP Poster! Find all posts View Profile Close Peterpilot]

I have your same setup - the shock length is fine - I have had all four wheels off the ground at 90km/h (near Finke - mis-judging a big hump), and I can assure you that even then, the shocks did not fully extend...

If you had ALL four wheels off the ground, I can guarantee you that ALL four of your Bilsteins were fully extended, as they should be

[Guest Close Guest]

The part number of the King Springs would be good too.

[Madkore Avid PP Poster! Find all posts View Profile Close Madkore]

King Springs (Medium) KTFR101 - as per another thread RedThing has posted in.

[GreenVX Junior Member Find all posts View Profile Close GreenVX]

Just a little more side info, the dobinson springs I have installed are heavy duty front and rear. They are designed to be level with a winch and bar on the front end hence why they hop, there just isnt enough weight to counter the compression and rebound of the coilover.
Also just curiously, what type/brand of tyres are you using at present? Road, All-terrain or Mud?

[Anth120playdo Banned Find all posts View Profile Close Anth120playdo]

KTFR-101 are a good spring for an inch lift.
Not 2 inches.
They usually ride and handle really well.
I have fitted them up with RAW 4x4 coil overs and they are excellent.
But you will only end up with 20-30mm maybe 40mm when first installed.

Don't know much about billies.

But there is a good chance the fronts fully extending on speed humps.
On prados, depending what full extension you choice of shocks has, there's not usually much down travel left after
A good 50mm lift.
If there is then the c/v will be on a big angle, it's then a matter of when.

[Peterpilot Avid PP Poster! Find all posts View Profile Close Peterpilot]

It is possible to get 2" of lift with Bilsteins on the KTFR101 spring if the spring seat circlip is set at the highest position and there is very little extra weight over the front axle. That's why we need to see the measurements from rim to guard at static and fully extended as per Andrew's post in order to compare and see if a lack of remaining down travel is the issue.

[Peterpilot Avid PP Poster! Find all posts View Profile Close Peterpilot]

Another thing to consider is to check all the strut retaining nuts and bolts are tight, especially the strut top nut and also ensure there is sufficient crush at the top bush, with no movement. I've seen two cases on Bilsteins where movement at the top bush allowed the bush to fail, resulting in metal to metal contact destroying both the strut top and damaging the strut shaft.

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

But there is a good chance the fronts fully extending on speed humps.
On prados, depending what full extension you choice of shocks has, there's not usually much down travel left after
A good 50mm lift.
If there is then the c/v will be on a big angle, it's then a matter of when.

I have a genuine 50mm lift (800mm bottom of rim to gaurd) and still have 95mm of down travel and a small diff drop kit means CV angles are not an issue.

A 50mm lift and suspension that doesn't top out over speed bumps is easily achieved.

As others have suggested some measurements might clear up a few isssues.

Cheers Andrew