Drain Plug Torque / sealing washers

[jetmechmarty]

The Clymer book is all that's available to me at the moment. My middle and final gearboxes have been drained. In one paragraph Clymer says to torque the drain plug to 31 ft lb. In the next, it says to tighten it to 17 ft lb. I assume 31 is the correct tq, but talk about confusion.

Does anyone here see a problem with replacing the aluminum crush washers with copper ones and using the same torque?

[bikerphil]

I wouldn't see it being a problem, can't hurt if you don't exceed the correct torque value, whatever that might be.

[James England]

The Clymer book is all that's available to me at the moment. My middle and final gearboxes have been drained. In one paragraph Clymer says to torque the drain plug to 31 ft lb. In the next, it says to tighten it to 17 ft lb. I assume 31 is the correct tq, but talk about confusion.

Does anyone here see a problem with replacing the aluminum crush washers with copper ones and using the same torque?

Why do you assume that the 31 ft lbs is the correct figure? I've always used copper washers and not used a torque wrench. I just do them tight but not too tight!

[jetmechmarty]

Why do you assume that the 31 ft lbs is the correct figure? I've always used copper washers and not used a torque wrench. I just do them tight but not too tight!

James,

I assume that because 31 ft lb is what comes up most often. IIRC, the oil drain plug is the same size and 31 ft lb is given for that. A calibrated elbow is usually good enough, but I like to use a tq wrench when it's available. It gives me a bit of added confidence in a job done right.

I've had pesky leaks with my final drive, and once I had the oil plug fall out after I let a shop change my oil.

Does the factory service manual agree that the drain plugs require 31 ft lbs of torque?

[JeffH]

I've always used copper washers and not used a torque wrench. I just do them tight but not too tight!

I agree with James! I'd be cautious about romping down on the middle and FD drive drain bolts to 30 ft lbs. While 30 might be the proper torque I'd go by what feels right to get it sealed up. If you rip out the threads then you got a bigger problem.

That said, I am using torque specs for most of the other bolts. I've just always been extra careful with drain plugs to #1 make sure they are secure #2 make sure they don't leak #3 make sure I don't strip them. Always extra cautious with spark plugs too. To me drain plugs and spark plugs are two items that are easy to mess up and hard to repair.

Jeff

[WMarshy]

This is the second post in the last 2 days where I have read about Clymer manual having mistakes for torque values. If I were you guy, I would through that thing in the fire and download the PDF version from C.Bug.

[jetmechmarty]

I'll do the final drive first. I have a spare.

[JeffH]

Torque Specs from manual

Here is what the OEM "book" says:

See Page 7-10, Unless otherwise specified torque specifications call for clean, dray threads. Components should be at room temperature. Torque specification 10mm=7.2 ft/lb, 12mm=15 ft/lb, 14mm=25 to 29mm, 17mm=29 to 33 ft/lb, 19mm=33 to 36 ft/lb. Since the Middle and FD drain bolts are 19mm then 33 to 36 ft/lb is the number.

If we reference Page 2-13 we see c. Reinstall the middle and/or final drain plug(s).
d. Fill the gear case(s) up to specified level.

No reference to torque spec. So, apparently since "Torque Spec" was NOT specified that we are to use Torque Specs on Page 7-10. Since drain bolts are 19mm we should torque to 33 to 36 ft/lbs.

I just got out my 19mm socket and torque wrench and gave mine another click!!! Before this I had 'missed' the Page 7-10 guidelines and was curious why some bolts had torque specs listed and many others didn't.

Jeff

[jetmechmarty]

Those drain plug threads will not be dry. They will be lube torqued. Thank you for posting that info.

[Irukandji]

Marty,,, middle and drain pan is 31 ft/lb from the tourqe page at the end of the service manual

[jetmechmarty]

Oil Reduce torque 15% to 25%
Dry Film (Teflon or moly based) Reduce torque 50%
Dry Wax (Cetyl alcohol) Reduce torque 50%
Chrome plating No change
Cadmium plating Reduce torque 25%
Zinc plating Reduce torque 15%

[natemoen]

Here is what the OEM "book" says:

See Page 7-10, Unless otherwise specified torque specifications call for clean, dray threads. Components should be at room temperature. Torque specification 10mm=7.2 ft/lb, 12mm=15 ft/lb, 14mm=25 to 29mm, 17mm=29 to 33 ft/lb, 19mm=33 to 36 ft/lb. Since the Middle and FD drain bolts are 19mm then 33 to 36 ft/lb is the number.

If we reference Page 2-13 we see c. Reinstall the middle and/or final drain plug(s).
d. Fill the gear case(s) up to specified level.

No reference to torque spec. So, apparently since "Torque Spec" was NOT specified that we are to use Torque Specs on Page 7-10. Since drain bolts are 19mm we should torque to 33 to 36 ft/lbs.

I just got out my 19mm socket and torque wrench and gave mine another click!!! Before this I had 'missed' the Page 7-10 guidelines and was curious why some bolts had torque specs listed and many others didn't.

Jeff

The drain plugs are all 14mm, not 19mm. It is rated on the diameter of the bolt shaft NOT the size of the socket used on the head.

[skids]

You don't need to tighten it down much at all to seal it if you use a nylon washer (14mm?). That is what came with the aftermarket plug when I stripped the threads. It is the cat's meow. I now use a nylon washer with the final drive fill plug also. It is so easy to remove that plug for maintenance.

[jwhughes3]

Oil plug bolts

I always tighten my oil lug bolts by feel....

"New girlfriend" tight = tighter than loose, but "not too tight"

That means everyone has a different definition

BTW if any of you tell on me to SWMBO I will git you!


John

[JeffH]

The drain plugs are all 14mm, not 19mm. It is rated on the diameter of the bolt shaft NOT the size of the socket used on the head.

Correcto, the Service Manual Page 7-10 has two columns for the General Torque Specifications. Column A is for mm "Distances across flats". Column B is for mm "Outside thread diameter. So for example, looking up the FD drain plug it is 19mm across flats. 19mm in Col A = 33 to 36 ft lbs. Get the same answer using thread OD which is 14mm. Col B for 14mm thread OD = 33 to 36 ft lbs. Table for the General Torque Specifications provides spec for either way using Col A or Col B depending on preference or measuring Flats across of thread OD.

Jeff