Differential Tags to determine fliud

[Outspoken1]

Hello everyone:

My wonderful neighbor is replacing seals, ball joints, tie rods, steering box (I'm not sure what that is), brakes and converting automatic to manual hubs on my 1993 Ford Ranger 4.0L.

We have the rear differential, rear bearings and seals and rear brakes completed. I am not sure what type of rear differential (other than knowing it is an 8.8 per the picts of the diff cover) so I don't know if I need to put in traction-lok and or friction modifier. The tag reads:
S859A
3L73 88 2L04

I think the 3L73 means Traction-Lok (from the example on the Front & Rear Axle Fluids page on Ranger Station), but I am not sure what that means. I don't know if that means I have a rear locking differential. I will be filling the diff tomorrow (March 24 - Monday), so I need to know what to put in.

We are also trying (and I mean trying!!) to remove the front Dana 35 to replace leaking seals. Again the tag reads:
610619 4 5 NOV 92 3.73
D-341-G
F37A - 3002 - ATA (I'm not sure about the "00" in the 3002 - the tag is smeared with green paint)

Again, is this a front locking differential (which needs 2 oz of friction modifier per the Front & Rear Axle Fluids web page)? I am not a 4-wheeler; I just use the 4-wheel drive when we have bad snow storms.

Thanks soooo much for your help,
Sandra

 

[Ranger44]

The rear 3L73. Means it has 3.73 gearing and yes, the "L" stands for limited slip. It will need a friction modifier added to the fluid. Your front axle wouldn't have a limited slip in it, so a regular hyploid fluid would be used.

Good Luck!

 

[kunar]

The rear 3L73. Means it has 3.73 gearing and yes, the "L" stands for limited slip. It will need a friction modifier added to the fluid. Your front axle wouldn't have a limited slip in it, so a regular hyploid fluid would be used.

Good Luck!

+1, and even for the rear diff, the friction modifier isnt required, unless you have a chatter or squeaking coming from the rear end when you turn. if the l/s pack makes noise, then you need the additive. for a lot of older vehicles, you dont need it.

 

[Outspoken1]

Thanks so much for the help. I will go to the store to get the friction modifier today

Take care,
Sandy

 

[Hahnsb2]

Neither are "locking" diffs. The rear is a limited slip, the front is open. You probably wont need friction modifier, I didn't use any with my LS when I had it and it didn't make any noise.

 

[Jackster]

I've worked in the parts dept.'s for 20 years at Ford dealerships. Working the shop counters for many of those yrears, I can tell you that friction modifyer (motorcraft part#XL-3) is used in all limited slip rears. In fact many technicions will soak the clutch packs in FM before installing them. Put it in first and top off the housing with XY75W140 synthetic oil. You wont go wrong.

 

[Hahnsb2]

I've worked in the parts dept.'s for 20 years at Ford dealerships. Working the shop counters for many of those yrears, I can tell you that friction modifyer (motorcraft part#XL-3) is used in all limited slip rears. In fact many technicions will soak the clutch packs in FM before installing them. Put it in first and top off the housing with XY75W140 synthetic oil. You wont go wrong.

Yes we know, but if they are the old clutches they will almost never make noise when run without friction modifier and you will get a bit better performance out of it in low traction situations.

 

[Jackster]

That makes sense. I was assuming he was putting new clutches in the rear.

 

[Sasquatch_Ryda]

I wouldn't use 75w140 in anything of mine, stick to 75w90 or 80w90, you can buy Penzoil 80w90 that already has the friction modifier in it.