Corral

rob · 10-17-2011, 07:08 PM

Anybody have tips on changing the oil if it's possible on oem style fox parts. Trying to stiffen them up and thinking 30wt would be perfect for what I'm trying to do.

Cannot use high dollar parts.

MFE · 10-17-2011, 10:57 PM

First of all, that's not how they work. The "stiffness" has very little to do with the weight of the oil, which by the way is very specific to the application of shocks and struts. You can't just put motor oil in them and call it good. The stiffness has almost everything to do with precisely sized orifices and stacks of spring plates that provide valving relief depending on shaft speed and acceleration. There are highly-degreed engineers who spend every working day fiddling with them to balance the tradeoffs, and if it were as simple as putting heavier oil in it they could all go home and look for other things to do. Lastly, they're almost all pressurized with nitrogen and you need a way to safely relieve that pressure before you can even think of taking them apart.

rob · 10-18-2011, 10:09 AM

See what happens when I get advice from import guys lol.

wizwrath · 10-18-2011, 10:28 AM

OMG....why are you talking to those rice burners?!?!!? You should be taking them out at the tracks!! lol....anyways, I use to do alot of the (factory equipment racing back then) and I think if your rules allow it, the actual OE parts replacement catagory was satisfactory, that means we use to go to a quality parts replacement place and get things like KYB or even Monroe's, and they had a OE replacement cross reference part number so it was allowed in our dirt track days......We use to drill a small hole in the shock to drain the oil and seal it back up in the fronts to allow quick extension on the drag strip....

Jim Brozynski · 10-19-2011, 03:16 PM

Back in the day front struts were not gas charged and could be disassembled and then re-assembled using heavier oil. When I did this on a Capri for use in autocrossing I used motorcycle fork oil. You only needed to increase the weight of the oil by a small amount to see a big increase in dampening. I had a friend that thought that if a little is good, more is better and blew out the seals of his struts when he used 50w fork oil instead of the 10 or 15w oil I used.

Modern struts are sealed from the factory so this options is no longer possible.

10-17-2011, 07:08 PM	#1
rob Registered User Trader Feedback: (10) Join Date: Nov 1999 Location: Virginia Beach, VA Posts: 1,858	Changing oil in shocks and struts Anybody have tips on changing the oil if it's possible on oem style fox parts. Trying to stiffen them up and thinking 30wt would be perfect for what I'm trying to do. Cannot use high dollar parts. __________________ 1982 Ford Fairmont Futura H/C/I, fuel injected and turbocharged 10.67@128

10-18-2011, 10:09 AM	#3
rob Registered User Trader Feedback: (10) Join Date: Nov 1999 Location: Virginia Beach, VA Posts: 1,858	See what happens when I get advice from import guys lol. __________________ 1982 Ford Fairmont Futura H/C/I, fuel injected and turbocharged 10.67@128

10-19-2011, 03:16 PM	#5
Jim Brozynski Registered User Trader Feedback: (2) Join Date: Sep 2002 Location: Chicago, IL Posts: 475	Back in the day front struts were not gas charged and could be disassembled and then re-assembled using heavier oil. When I did this on a Capri for use in autocrossing I used motorcycle fork oil. You only needed to increase the weight of the oil by a small amount to see a big increase in dampening. I had a friend that thought that if a little is good, more is better and blew out the seals of his struts when he used 50w fork oil instead of the 10 or 15w oil I used. Modern struts are sealed from the factory so this options is no longer possible. __________________ "Drag racing is for those people who don't know how to down shift and brake at the same time. " DD '00 SVT Contour, Race car '87 ITA 16V Scriocco Cars owned: '86 Mustang GT, '92 Mustang LX, '93 Mustang Cobra "R" #58

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10-17-2011, 10:57 PM	#2
MFE Super Moderator Trader Feedback: (8) Join Date: Nov 1999 Location: There Posts: 8,957	First of all, that's not how they work. The "stiffness" has very little to do with the weight of the oil, which by the way is very specific to the application of shocks and struts. You can't just put motor oil in them and call it good. The stiffness has almost everything to do with precisely sized orifices and stacks of spring plates that provide valving relief depending on shaft speed and acceleration. There are highly-degreed engineers who spend every working day fiddling with them to balance the tradeoffs, and if it were as simple as putting heavier oil in it they could all go home and look for other things to do. Lastly, they're almost all pressurized with nitrogen and you need a way to safely relieve that pressure before you can even think of taking them apart.

10-18-2011, 10:28 AM	#4
wizwrath Registered User Trader Feedback: (8) Join Date: Aug 2006 Location: Hawaii Posts: 733	OMG....why are you talking to those rice burners?!?!!? You should be taking them out at the tracks!! lol....anyways, I use to do alot of the (factory equipment racing back then) and I think if your rules allow it, the actual OE parts replacement catagory was satisfactory, that means we use to go to a quality parts replacement place and get things like KYB or even Monroe's, and they had a OE replacement cross reference part number so it was allowed in our dirt track days......We use to drill a small hole in the shock to drain the oil and seal it back up in the fronts to allow quick extension on the drag strip....