front diff. lube

[3mikeman]

I have A 99 silverado 2500 with push button 4-wheel drive. The front differential calls for 80w90 gl-5 lube is it ok to use mobil 1 75w90 synthetic lube. Would this cause any problems noise etc..

[wafrederick]

Use what it is called for.Synthetic gear lube can do damage,break parts and Currie has proven this.They will not warranty one of their rear ends if synthetic gear lube is used.

[ukrkoz]

I have Amsoil 75W90 in front diff for 2 yrs already.

[ricebike]

Originally Posted by wafrederick

Use what it is called for.Synthetic gear lube can do damage,break parts and Currie has proven this.They will not warranty one of their rear ends if synthetic gear lube is used.

really???? where in the book does it say that???

[wafrederick]

I read about this on another message board and call Currie on this

[toddman67]

Do what the manufacturer says especially if you have the G80 code on the lable in the glove box. Use a lubricant with the GL-5 additive or you will be sorry. Code G80 means it has a locking differential and it will "lock up and come a part!"

[j cAT]

Originally Posted by 3mikeman

I have A 99 silverado 2500 with push button 4-wheel drive. The front differential calls for 80w90 gl-5 lube is it ok to use mobil 1 75w90 synthetic lube. Would this cause any problems noise etc..

NO! I use the GL5 since 2000 with no problems on the front diff......replacing the fluid when discolored is required or damage will occur...

fill to 1/2 in below fill hole....and make sure the vent is not resticted [hose]....

you must check your fluids every oil change for level and condition....

[ukrkoz]

Originally Posted by j cAT

fill to 1/2 in below fill hole....and make sure the vent is not resticted [hose]....

Actually, owner manual says to "add fluid if level is slightly below the filler hole".

Now, in GM wisdom, same manual does this:
1. tells you to add as above
2. Tells you to keep it at 1/2 inch BELOW the filler hole ON COLD
3. tells you to keep it AT HOLE LEVEL ON HOT.

go figure. it's a strange book all through, every time i deal with it, i am wondering who wrote it. sort of "microsoft help" style - only microsoft programmers really know what it means.

as of 'recommended fluid", it bluntly tells you to go and consult with "recommended fluids" section - except that there is not mentioning of the front diff in that section at all, period, end of sentence. transfer case - yes, no sweat. front diff - nah-ah.

[j cAT]

Originally Posted by ukrkoz

Actually, owner manual says to "add fluid if level is slightly below the filler hole".

Now, in GM wisdom, same manual does this:
1. tells you to add as above
2. Tells you to keep it at 1/2 inch BELOW the filler hole ON COLD
3. tells you to keep it AT HOLE LEVEL ON HOT.

go figure. it's a strange book all through, every time i deal with it, i am wondering who wrote it. sort of "microsoft help" style - only microsoft programmers really know what it means.

as of 'recommended fluid", it bluntly tells you to go and consult with "recommended fluids" section - except that there is not mentioning of the front diff in that section at all, period, end of sentence. transfer case - yes, no sweat. front diff - nah-ah.

if you live in phoenix, AZ and your GL5 has been sitting on your deck in the sun on a hot day prior to adding/replacing the front diff gear oil ,,,I would fill to top of hole....