More getrag help please(specs)

[MMiller]

OK guys, so you know I had my first getrag troubles since my truck has been out of warranty. I've got to get new bearings and reassemble the transmission. James puts them together until the "feel" right. My feel-o-meter is probably out of calibration, so I need to know the "proper" preload for the bearings. My 1992 FSM says . 006"-. 008" of preload. Is this the correct setting? mysteryman? What say you?



Who here has the PDF of the getrag rebuild? Is the spec in there? Will somebody please send it to me?



I know for a while whoever was assembling these for Dodge, was setting them too tight. I want to make sure the . 006-. 008 is not the old "too tight" setting. That and James lives too far away to come help me put it back together, so I guess I'll do it myself. I guess I'll have to be the midwest getrag transmission rebuilder, and James can take care of the SE U. S. :-laf



Michael

 

[pepecat]

mysteryman's getrag info from ARCHIVES



Here is an excerpt of what you want from there (he says +. 006 for new bearings and . 000 for used):



"The bearings in the Getrag are Timken tapered roller bearings just like the front wheel bearings. On front wheel bearings you adjust the clearance with the spindle nut... . On a Getrag you stack thin shims..... For new bearings you want a +. 006 preload . For used bearings you want . 000 clearance.....



Back in the early 90's we were having problems with the remans getrag was sending us... I had about 20 or so that we tore down to find out what had happened... I found that all of them had +. 030 to +. 045 shim packs..... I thought that I was not calculating it correctly or that the failed units were too bad off to be accurate...

I went to the getrag reman plant way back when to get to the bottom of what the problem was..... I pulled 3 off of the line and tore them down to check the clearance... . They all had +. 030 to +. 045 shim packs in them as well..... Oh sh** ! I called for the production manager ... . We discussed my findings... He said that they set them up this way intentionally because they felt . 006 was too lose and caused excess gear rattle during testing... OMG !!!



I promptly told him that he was to stick to the spec that WE told them to use and that I was going to write my report to my superiors that Getrag was the cause of the failures and should be back charged for the failures of the remans that Chrysler had had to eat in the previous 3 years! "



And You're welcome... (new members take note) Do you know how to look up a tdr member's posts? Try reading thru Terry's aka mysteryman's posts he has other getrag info ++ more useful info.

 

[1stgen4evr]

Well I would not put NEW bearings up with . 006 preload. That is just too tight. And 460k miles on my 93 Getrag agrees with my opinion. If the setup were wheel bearings and each bearing was the size of the front and rear mainshaft bearing, I expect that they would run in without a problem at . 006 but the pocket bearing is so much smaller that the 'crush' is actually imposed on it to a greater degree.



To calibrate your feel-o-meter, do this even after you see it in print as to the preload. Set the preload to what you think is zero using micrometers and whatever method you feel works. Feel how the shaft rolls. Remove the rear housing and add shims to have the . 006 . Snug the bolts and rotate the (cluster/countershaft first) shaft. New or old bearings either one, now tell me it isn't too tight. From that, go back to what you think is . 002 preload. I use the term 'think' since all that you are doing is subjective in terms of using the micrometers and what you 'measure' can be different from what someone else measures since even using the micrometer requires a developed feel. Now tell me isn't that better.



Lets go back to what has to happen after you preload to . 006. The ends of the rollers in the bearings has to burnish down (rub off) to accomplish the 'run in'. Those boogers are quite hard and put up a fight in the rubbing off process. When (as I mentioned) you put that rubbing off more on the pocket bearing than the rest, you can roast that poor little devil before you get it 'run in'.



I know I said do the countershaft first where there are only the two bearings. This simplifies what you are trying to develop as to feel and when you get to the input/mainshaft preload, you will be a little more ready to feel that one. Remove the shims from the first setup and do the second shaft. I remove the shims so that I don't get any resistance to my 'feel' on the second shaft since all the mainshaft is gear connected to the countershaft. If you are working with . 006 you will definitely feel the first shaft preload as you try to feel the mainshaft preload.



You may need to take the transmission back out after a couple hundred thousand miles and reshim but you won't spend any more money on it.



Have I left out anything? Open for questions.



James

 

[MMiller]

Thanks for the information. I know as well as anybody does that the info is in here, but for some reason the "search" function just does not work for me. I end up with pages and pages of posts and my eyes end up bleeding way before I find what I am looking for.....



No questions right now James, I guess I'm going to get new bearings somewhere today, then I'll start setting them up. Then I'll see what the rolling torque feels like.



Michael

 

[pepecat]

No problem. I am glad to see that you have faith in the getrag in that it is a sound transmission if setup & cared for properly.

 

[MMiller]

No problem. I am glad to see that you have faith in the getrag in that it is a sound transmission if setup & cared for properly.

After taking this one apart and seeing the good shape its in, after the beating its had, I have no problem putting it back togther with new bearings and run it some more.



Michael

 

[dpuckett]

JLEONAD has the Getrag manual in PDF. I also have a copy of said manual printed out that I could send to you if you'd like- bring it back to SOP3.



Daniel

 

[MMiller]

JLEONAD has the Getrag manual in PDF. I also have a copy of said manual printed out that I could send to you if you'd like- bring it back to SOP3.



Daniel

Thanks Daniel, but hold that thought for right now. Actually as of right now at 9:30 pm, I am in the hunt for some shims. I got a $113 dollar bearing kit locally(wife drove 4 hrs round trip to have it today) and it came with NO #$^&&* SHIMS. I'm still hoping to have it together before weekend.



Michael

 

[BSchindler]

There is no comparison between wheel bearings and transmission bearings, tapered roller bearings or not. The mounting position determines wether the bearing is set up with preload or free play. If the "axle" is stationary (wheel spindle), set up with free play. If the "axle" is rotating (transmisson), set up with preload. The "specs" are determined by the size of the bearing, speed of rotation, and the designer. I believe a dial indicator and magnetic base would work better than "feel". Good Luck