Hello everyone, I am a new member of this awesome website. I have owned my 92 for almost a year and I enjoy the old machine. I have done alot of research on this Cummins diesel, having been in love with diesels since I was very young. I won't own anything else. Now on to the point of the post. I have a question concerning my Getrag 5spd. When the the truck is cold, almost exclusively during cold weather, the tranny grinds in 3rd and 4th. If I speed-shift from 2nd to 3rd, I can generally avoid any grinding, and if I give the truck royal hell in third I can avoid grinding in fourth. Also, while my clutch has been dubbed healthy by a trusted mechanic, the friction point is about 1/8" off the floor. Could this contribute? I believe synchros are at fault...am I right? Any ideas would be appreciated.

 

i cant tell you for sure i have had people telling me that
the getrag has shifting problem mine shifted like a dream
right up to the point it came apart in a big way so i am
currently getting ready to do the nv4500 conversion
i did run the extra quart of oil in it and a filter kit yet
it failed at 110,000 miles and my stock clutch still looked
like new

 

With the truck parked, engine running, transmission in neutral, one foot on your brake pedal and the other foot on the floor mat, GENTLY, as with one finger and thumb, move the shifter toward the gears that grind. Does it try to go into gear or do the syncros start to wind up? If it grinds as if you were doing this same procedure but were trying to put it in reverse I would suspect the transmission. If this checks out ok I would then do a gear oil change doing the "overfill" method using the proper synthetic lubricant. Possibly the transmission has the wrong grade of lubricant, probably 90 wt oil.
Clutch engagement position could indicate trapped air in the system. Bleed system at the slave cylinder and check for leaks.

 

Put Redline MTL in the trans, it will shift much better.

One of the common problems with the clutch linkage is that the plastic bushing between the pedal and the pushrod wears out. Once it is gone, there is metal-to-metal contact and the pushrod and pedal pin wear rapidly. When I got my truck, the pedal pin was worn about halfway through. If your clutch pedal sits lower than the brake pedal, this is almost certainly your problem. I fixed mine with a rod end and a bolt for about $10.

 

I would say it has 9ow in it some one had put this in mine when I bought it. Say dose ever one put the getrag one qt over full? Is this really better on the transmission? Thanks TBoling

 

Yeah, they don't shift real well with 90W, the PO did that to mine too.

Mine's 1.5 qts overfilled. The idea is to try to keep the input bearing well lubricated. Mine is holding the power so far.

 

I'm going to test it as recommended; I will let y'all know what happens. Thank all of you for your sage advice. While I am writing, I have another question. If I just apply pressure to my brake pedal I have roughly zero stopping power , but if I pump the pedal repeatedly first, I have decent brakes. I had shoes put on the drums not too long ago, and I am pretty sure the pads up front are in good shape. I am constantly losing brake fluid, and there is a constant dampness around the master cylinder. Should I look for a line leak, cylinder leak, and possible cylinder failure? Thanks for any ideas.

Keith

 

If the fluid is running down the booster its the MC, mine did that, you should be able to see it. if its leaking change it pronto, the fluid can damage the diaphram in the booster. A soft pedal usually means air in the system,

 

If brake fluid is getting out, then air can get in. Solve that problem and the spongy pedal will go away. Getting every last bit of air out of the lines is critical to good pedal feel. None of the parts involved are very expensive, but it is a little bit of work, and usually requires an extra set of hands to bleed the system.

 

It's definitely a leaking master. They're about $25 rebuilt. If this has been going on for more than a few weeks, I would change the booster while you have the master off. Like loch said, the brake fluid will eat the diaphragm in the booster. Replacing both parts at the same time will save you the hassle of pulling it apart again in a few months when the booster fails.