Do all Getrags rattle when lugged? I got to keep the rpm's up to keep it smooth. Been this way for yrs. Going to try some synthetic oil and see what it does.
How much do I need to install to get it to the proper "overfilled" point?

 

Recommended procedure is to drain and fill with FIVE quarts of MOBIL-ONE FULL SYNTHETIC 5W-30 oil.

Walmart right now has five-quart jugs on sale for twenty bucks.

In order to overfill, and later be able to check the level, there are about as many tricks as trucks, with the most common being to replace the filler-plug with a street-ell, pointing up, and a short nipple in the street-ell will give a little lee-way for filling.

Some simply dump the extra oil through a PTO bolt-hole, or through the shifter; but, these methods allow no provision for checking the level.


DO NOT LUG a Getrag, or any other transmission, for that matter.

It isn't actually the Getrag that is the problem with lugging, so much as the tremendous low-end torque output of the Cummins.

 

I never lug it under any torque. It just rattles at any lower rpm, even coasting. Driving thru town in 3rd sometimes calls for a higher speed or a downshift. Worse when hot.
I was just wondering if somethings a little loose that could be "shimmed up" easily. I'm sure its getting close to clutch R&R time anyway.

 

No, the low RPM rattle is normal, although disconcerting. I think I saw a recommendation from Mystery Man about allowing it to do that being detrimental. I always try to downshift or go into neutral whenever I sense it coming on. I get it coasting between 800-1100rpm in 4th or 5th.

 

To be honest, the three that I have are all quite; although they will complain when lugging them, there are no rattles/noises otherwise.

Quiet when coasting, quiet when shifting, quiet when sitting still with clutch in or out.

 

Mainly noticable in 3rd and 4th when unloaded, just maintaining speed on flat road. If it starts to rattle I can apply more throttle or downshift and it will stop. Its been this way for a couple of yrs but seems to be worse now. OK when its cold. It's just annoying and a bit worrisome.

Also, I've noticed a "clink" of slack in the driveline when shifting. Not sure if it's a u-joint, diff or in the gearbox. I'll have a closer look this weekend when I do the fluid change.
What diff fluid is good for these old beast?

 

Well, this is kinda off topic but I didnt feel the need to start a new thread over a related topic.
Which would be the best trans to drop into, lets say my 93 4x4 Automatic, to convert it to a manual?
Getrag?
NV4500?
NV4600?

And by best I mean which would be easiest, cost effective, more reliable, ect.?

Thanks

 

Well you know from mine that there is none really cost effective. Although my getrag was probably the cheapest route. With my gearing still at 3.07s, an NV5600 would be great, as theres quite a bit of spacing between the 5 gears in the getrag for my rearend. The 5600 6speed is closer spaced, and hopefully I drop one in mine someday.

 

x2 here. Its bout time for me to change mine too, since it hasnt been done in my 70k possession .

 

Well the Getrag was more or less a direct bolt in, correct? But with a 4500 or 5600 would I have to redsign tans brackets? Will my t-case bolt right up no problem or will I have to change input shafts and what not?
Im not planning on doing the swap anytime soon but Id like to start shopping now. Plus my friends in galveston got their hands in just about every junk yard in galveston so im sure I could find what I want cheap, if not free. =D

 

You'll want a synchromesh type fluid, Pennzoil makes one, RP Synchromax, Mopar brand (expensive!) other as well, I'm sure. They are much better for the trans than any motor oil, synthetic or otherwise.

 

If the rattle happens at low RPM (under 1500) I wouldn't sweat it, just try to avoid doing it.

If you can't find the slack in the u-joints and the rear axle isn't howling, then it's a worn cross pin (open diff) or worn out clutch packs (limited slip diff).

 

I use 85W-140; but, I tow long-distance and heavy.

A street truck would be okay with 85W-90.

Just make sure to add a couple tubes of that funny-smelling stuff for the limited-slip.

Some gear-lubes include this stuff in the mix; but, none of the bottles that I have been able to find make any mention of having it.

Be sure to also remove and examine/clean-out the axle vent tube, making sure to probe out the fitting that screws into the rear-end, as it will be plugged with junk.

A stopped-up axle-vent is the cause of most pinion-seal leaks.

 

Will overfilling the Getrag smooth out the shifting and enable faster shifting? Mine takes a bit of pull to change gears and going into 3rd definitely isn't smooth. Some may be my technique or lack thereof but shoot, it's not the smoothest shifting vehicle, and I've seen videos of people shifting fairly quickly on here. I can't do that with mine! If putting an elbow & extension tube on the fill hole, is there a good tube length to use above the elbow to have 1 additional quart be at the top of it?

Also, where does everyone's clutch engage? Mine is right at the top end, so you have to let it out a long way before engagement.

Hope this wasn't too much of a hijack , but it seemed like this was a general Getrag thread.

 

My Getrag started behaving noticeably better when I overfilled it with Royal Purple Synchromax.