[Mid Life Crisis #388]

I believe FordBullitt had mentioned this in a post months ago.

Finally got around to trying it. Changed the Differential fluid with Red Line oil's ShockProof lightweight (75W-140). They say it has the lower internal fluid friction of an SAE 30 motor oil.

All I can tell you is that it removed a LOT of the klunk that I had been getting in the drive line.

Even stuck in rushhour traffic coming home today I could not hear the usual small klink or the larger klunk, when lazily shifting gears. Then I tried to make it do it and could not. This may not get rid of all of the drive line noise but it certainly made a huge difference in my case.

I did not want to crack the cover so I used a vacum pump setup and was only able to get out 6.5 cups of the advertised 8 cup capacity. Figure I would wait a few months and then take out another quart and add it back.

Here is some more info
http://www.redlineoil.com/redlineoil/spgoti.htm

 

[merc50]

Is the driveline clunk happen only when pushing in or taking out the clutch pedal? I get a klunk-klunk now. I took it in and they said it was normal...agh!!!! It seems to have gotten more noticeable over time...but I haven't noticed any detrimental affects from it. It still hauls and shifts great...just only when driving slow...backing up or pulling foward do I usually notice it.

John

 

[Mid Life Crisis #388]

It would happen mainly when up shifting and because of traffic, you would not keep accelerating but kind of stay where you were. Same when down shifting, kind of like you could have just stayed in that last gear if you weren't going to keep going or slowing. Guess you could say the drive line was makng noise when it was unloading and changing direction.

 

[5111]

Yeah, I get that clunk all the time, especially when driving in stop and go traffic. If I pay attention then I can keep it from happening though.

 

[Mid Life Crisis #388]

Just an FYI Update to using the Redline Shockproof medium weight rear end fluid.

I was reading an article how they took a Vette and changed all the fluids over from factory fill and with a dyno showed an increase in HP. Then put the stock fluids back and showed the drop again. Also they filled the rear end with the redline shockproof oil and added friction modifiers.
That made me wonder, I asked the salesman and Redline's tech department, that for the shockproof oil, medium weight, do I need to add the friction modifiers? Both said NO. So why did they in the Vette test.

Wrote Redlines tech department and asked again if I needed any friction modifiers for the rear end using the shock proof.

Got back a no but they did not recommend the shockproof for my car anyway. That was made for race conditions and that the tech would not recommend it for everyday use. Kind of weird I thought. He recomended their straight 75W-140. Well the ONLY 75-140 I see on their site is for rear ends that DO NOT have limited slip gears.

SO I looked at Mobil 1 and could not find 75W-140, so I went with the Amsoil 75W-140 instead. Dealer told me that Mobil makes the Ford over the counter 75W-140 and it is the same price as the Amsoil.

I still have had the best luck using Redlines D4 ATF in the transmission though and no improvement using the Amsoil ATF.
Guess you have to just keep trying different things that work best in your own car.

 

[Kngmke1]

So Mid life, did you remove the Redline 75-140 from your rear or not? Iwas going have it put in when I did the gear upgrade. Performance here recommend it & Ford's magic bottle of Friction modifier.
By the way, I swapped out the rear tokicos this weekend with the VST's, big difference another good call...
thanks

 

[Mid Life Crisis #388]

Hi Kngmke1,
Yes I took it out and put in the Amsoil. Not sure why but the Mobil 1 oem and the Redline oil sure stunk...... I still have it in my nose. Figure if the Tech is telling me it is NOT for me and if they were going to contradict themselves that I would just take it out... NOT sure why they would say it was for racing and not suitable for everyday street, but seeing as I have no power mods I figure it would not make much of a difference to me.

So you can feel the difference with the shocks???
Sure seemed like a big difference to me and for only $40.
I have certain bumps that before I could feel the rear end fly over and now I can feel the rear end drive up and then down the bump....

 

[BITETHIS]

you may want to check the vibration dampner in front and under the diff my bolts were loose i tightened and it helped some i think there is just too much play in our driveline for some reason

 

[LesnTea]

Mid Life, I use the Red Line 80W140 which contains additives for limited slip differentials.

I always order the Red Line from Autoil.com they are super fast on shipping, and reasonably priced.