Rear bumpstop extensions

[Brad_kosij Member Find all posts View Profile Close Brad_kosij]

Part way through installing the 4" superior kit into the 06 120 prado and was looking at the factory rear bumpstops

As far as I can see from factory the rear outer bump stop (little one) is the only one thats been hitting

Now I have searched and have only found info bout buying blocks for the outer ones from like monster rides etc

My measurements are 195mm till rear shock is bottomed out and 180mm between bottom of bump stop (inside coil) and diff.

How much bump stop compression do u guys use, in my comp hilux I run 4runner rear bump stops and allow for 60mm of compression at full bump and I believe still on occasions I top out the shock.

Cheers brad

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

The bumpstop is the one that contacts the diff housing and you refer to as the outer bumpstop. The hollow rubber inside the spring has no load carrying ability and is actually removed to fit polyairs. Where exactly are you measuring 195mm from?

The only measurement that matters is from centre of bottom shock mount bolt to top shock mounting point at full compression, this will tell you what the maximum compressed length of a shock needs to be to avoid bottoming out and how much you may need to space the bumpstop. As far as topping out is concerned, there is no top bumpstop so it is normal to have the length of the shock being the limiting factor for maximum extension as long as you have lengthened rear links, otherwise the sway bar is limiting.

[Brad_kosij Member Find all posts View Profile Close Brad_kosij]

Sitting at ride height 195 is the amount of shock piston available, so I can measure 195 piston length, fully compressed there will be 0 piston showing.

As far as I can see the bump stop inside the coil would be used for full hard bump to stop shock from running out of piston stroke so it dampenes the bump where as the outer one would be more for wheel travel when the eg- drivers side s flexd up (shock fully closed) and passenger side extended (shock extended), then the one on the outside of the coil would contact the diff housing

The outer one is only tiny so I wouldn't think it would take much load at all.

Think if you were driving down a road and you hit a BIG pothole the whole rear suspension would travel up square to the body and the bumpstop inside the coil would dampen the shock before the shock runs out of up travel (so shock is compressing).

Know what I mean

Brad

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

Ok, at "195 piston showing" how much clearance do you have between the bumper and the axle housing? For the sake of your shocks as long as the bumper is reached before there is "0 piston showing". Disregard those rubber cones inside the coil, they don't provide bumpstop protection.

According to toyodiy, the left bumper is part number 48036 and the right bumper is part number 48306A:
http://www.toyodiy.com/parts/p_G_200...AEKQ_4804.html

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The outer one is only tiny so I wouldn't think it would take much load at all.

The outer one will take the load of the rear half of the car. This is through experience when my rear airbag popped and we drove 300km really slowly from our holiday destination back home. The car was pretty much empty as we drove the Prado home to collect our 2nd car to continue the holiday.

[Brad_kosij Member Find all posts View Profile Close Brad_kosij]

Measurements on outer bump stop between diff housing and tip of bumpstop was approx 220 drivers side and 230 passenger side.

Not sure how much compression I should allow, I find it strange that the outer one is the one that gets extended as its different to how I'd set it up in my coiled hilux..

So just looking purely at the figures I have a difference of 25-35mm so would expect a spacer of at least 60-70mm to ensure shock doesn't top out? Sound right or am I way off?

Thanks brad

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

Spacing the bumpstop by 70mm seems a bit much. What rear shocks have you got? What's the compressed length of the shock?

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

Another thing you may consider is using the longer bumpstops from the Grande, left bumper part number 48036 and right bumper part number 48306A: http://www.toyodiy.com/parts/p_G_200...KQ_4804.2.html



The Grande bumpstops are about 105mm long from chassis mount to end, how does this compare to your current bumpstops?

[Brad_kosij Member Find all posts View Profile Close Brad_kosij]

I'm running the superior profender 4" kit, so there a remote res profender shock

Length:Open 670mm/Closed 405mm

The bump stops are approx 60mm high

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

Nice, the standard shock is 356mm closed so only 49mm shorter than 405mm. This means that a 50mm bumpstop spacer is more than enough. In fact, other forum members have fitted 80 series rear shocks with a closed length of 370mm with standard bumpers, so you would probably be OK by spacing the bumpstops 35mm. I suggest taking your own measurements to make sure the shock isn't longer than 405mm closed.

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

The bumpstop is the one that contacts the diff housing and you refer to as the outer bumpstop. The hollow rubber inside the spring has no load carrying ability and is actually removed to fit polyairs.

You actually don't remove them, just cut them shorter, but I agree they are not the limiting factor for up travel.

Cheers Andrew

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

I run 6" 80 series shocks , and only had to extend that outer bump stop 30mm ..

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

I run 6" 80 series shocks , and only had to extend that outer bump stop 30mm ..

Sounds about right to me, what shocks you got in yours?

[Brad_kosij Member Find all posts View Profile Close Brad_kosij]

Thanks for the reply's
Yeh I took in the info you guys suggested and looked at the measurements again and decided on 45mm extensions, so when I get the rest of the gear I'm waiting on from superior eng (pretty bloody slow as I've been waiting nearly 2weeks) ill take it to all barred up customs and run it up the travel ramp again and see how things look.

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

Sounds about right to me, what shocks you got in yours?

I have dobinson 80 series 6" shocks , I forget the exact measurements now.


When ya go up the travel ramp you'll fine your lower arms will bind on the housing, that's why u get the superior lower arms get heaps more flex and than the handbreak cable gets too tight .. Tailshaft hits the fuel tank but only at full flex , umm and I'm running a 33" tyre and when it tucks that's what was stopping my flex rather than the bump stops on the diffs.