New Owner with Rattling Getrag

[RedRamAndy]

Hello All,

Glad to finally be a diesel owner and a new part of this fantastic forum. I've learned so much already by sifting through the archives. I've been searching for a deal on the right truck and found it by accident after 3 years of hunting (at least I hope it's the right truck).

I never knew about the quirks and issues of the Getrag until now. My Getrag has a substantial rattling sound when idling in neutral. The previous owner said he thought it was a throwout bearing and it had done that for the last 30k miles. However, I was suspicious as the noise does not disappear until the clutch is completely pushed in. It also changes character as I raise the RPM. I bought the truck anyway as the price was way-right. When I got home, I started toying with it and noticed a lot of clicking/gear noise when I'm in 1st or R and lightly blip the throttle to reverse the lash in the trans. Also when I shut down the Cummins, I hear a hard transmission rattle as the engine quits. The clincher of this whole issue is that I can change the rattling sound in neutral to a light gear grind if I apply slight pressure to the shifter in any direction.

I'm sure I need a rebuild, and want to catch it before it grenades. I suspect there are worn bearings and slop in the clusters. I've already done what any newbie should do and got the full truck FSM and the diesel FSM supplement off e-bay (total of 68 bux, woo-hoo!) I actually look forward to doing this and am looking for any advice I can get.

I would rather not drive it anymore, but have to make about a 5 mile trip for the inspection/license routine. I'm not too worried as I am told it has done this for so long. The previous owner bought it at 141,000 miles and replaced the fluid with the same that came out, Dexron. I'm sure he didn't know about the overfill trick either.

What's your feeling on a PTO cover filter kit? And the $100 bearing kits on e-bay? I've read about the cheap 3-4 shift forks and am scared about getting substandard parts.



Thanks so much for you time!



Educate me.

 

[1stgen4evr]

The right truck? Educate me.



Hang on you are about to get educated big time. (Not by me but by the truck) And you got the right truck to do that.



A rattling Getrag can be an instant grenade but if it has been making the noise for three years and isn't getting quickly worse, you have a little time, but not much. I have known situations where the transmission instantly quit going in all but fourth.



Are you two wheel drive or 4x4? The four wheel drive set up will stay together longer since the transfer case supports the main shaft better and the getrag can really grind itself to nothing. Either way, you will need to tend to the problem as it will only get wor$$$$$$$e. You can run the transmission till it isn't buildable (at an afordable price).



I have done a few rebuilds and there isn't just one single thing that is the magic formula but bearing slack is the most common problem. You can remove the pto covers and check for preload on the upper and lower shafts. There should be zero slack forward and back on either one. You can inspect the magnet in the bottom of the case and with a light see quite a good bit before removing the transmission. But--- the noise isn't going to disappear. Get on it. Anticipate more than bearings and be thankful if that is all it needs. And by the way, it could be clutch noise for the most part. They can fool you.



James

 

[RedRamAndy]

Thanks James!

I do plan to get on it quickly. The random rattle changes to a clear grind when I lightly touch the shifter. The sound of each of the clicks stays exactly the same, it just fills in from 'random' to 'grind' upon the lightest touch of the shifter. This is what tells me to 'get on it' too. Thanks for the push.

I have a 2wd. Possibly I will pull the PTO cover and have a look this weekend. I'm anxiously awaiting my manuals in the mail for now. Thanks for the info.

If anyone else has any pointers for a Getrag Novice, please advise. My bag has been old Mopar muscle performance with 727 Torqueflights mainly. I'll be relying on the books and help from this forum for this Getrag. This truck is a real kick for me to drive. I'm thrilled and don't want to mess it up!

Thank you much!

 

[dpuckett]

FLUID- You need engine or gear oil in there- not ATF. Second, it sounds like you have a throwout bearing issue if the noise goes away with full disengagement of the clutch. Rattling when trying to put it in gear with the clutch engaged isnt abnormal.



I have yet to have a manual truck transmission that doesnt make SOME noise at some time, but it can get expensive fast.



I got my bearing and synchro set from Zumbrota Bearing and Gear in Zumbrota MN. Roger (G/f's boss -runs an suto shop, and they stay BUSY) said he had dealt with them before, so I figured it was good enough til I got the $$ for a 6 or 7 speed conversion :-laf. Kit came with Koyo bearings, which is what was in the reman transmission.



Daniel

 

[RedRamAndy]

Tonite I drained out the old Dexron and pulled the passenger's side PTO cover to have a look. The gears all look very nice and no metallic came out with the oil. I can hear and see a good deal of gear lash and 'clunk' as I grab the driveshaft (2wd) and twist. The counter shaft seems tight with no fore-aft play. The gears on the upper shaft seem to have about 0. 015 to 0. 020 play along the shaft.

What else should I inspect after I pull the second PTO? I want to check everything before I overfill with 15w-40. I'm hoping my rattle goes away, and I guess I'll try to plan a rebuild soon? Where is the 'pocket' bearing?

What's my best plan?



Thanks a bunch.

 

[1stgen4evr]

The pocket beaing is between the input shaft and the mainshaft. You can not see it till disassembly. The gears have some slight end play on the mainshaft but the shaft assembly should be snug on the bearings at the ends of the shaft. With the upper shaft, there are the three bearings that work as a unit. Begining to sound like you have a clutch issue and perhaps not a transmission issue. Try the motor oil and do the extra quart overfill. See what the result is.



James

 

[RedRamAndy]

Thanks James! I will do that and keep hoping. However, if I do have to replace that clutch, I think it's going to be hard to keep me out of that transmission while it's on the floor... . :-laf

 

[1stgen4evr]

hard to keep me out of that transmission while it's on the floor.



Of course. At the very least, take the top off and have a look around. Syncros, teeth, input splines and pilot bearing tang, etc-------



But keep an ear tuned to the noises. Anything new and out she comes. Experiment with shifting technique and see if you can derive a method that smooths out the noises. It might be worth noteing that low rpms shifting up will bring out a rattle from the clutch/transmission. Try more rpms before the shift.



James

 

[RedRamAndy]

Getrag Update:

This Saturday I got to refill the Getrag (1 qt. overfill) with 15w-40 and this has changed things a bit. Now the rattle, at idle in neutral with clutch out, that I had before has changed into a constant light clicking as gearteeth passing each other. This is the same, but quieter sound I experienced before when I pushed the shifter around. The interesting part is, if I push the shifter about 3/4" towrd the dash, it stops. All is quiet.

What should I do/look for?

The old Dexron that came out was clean except for VERY few non-MAGNETIC flakes.

 

[1stgen4evr]

Just a guess but an experienced guess. You may be getting a problem with the detents on the shift rails. There are springs and balls riding in detents (notches) that hold each shift rail in a (designed) position. There is a notch for neutral and for each particular gear. If the noise goes away by lifting the stick up a bit, you may have a notch that is worn or a spring broken that isn't holding the (ultimately the fork and gear) where it should be in a neutral position. You may not want to cut a hole (actually the top of the hump and some down the sides) in the floor but the shift assemble can be lifted off if you do that. You can then do whatever is needed to anything in the shifter. You may also have a bent fork from heavy handed shifting.



I have not done the hole cut thing. If you decide to do that, get advise from someone (TDR) who has.



James

 

[WJune]

Three things I would recomend to any new Getrag owner.



1. Change fluid and check for metal particles.

2. Install filter kit.

3. If you suspect any problems, cut hole in floor, remove shift assembly to inspect syncs and alum. shift forks. Personaly I cut the minimum size hole. I use the removed piece as a pattern for the oversize piece which is then reinstalled. One careful cut in the carpet and its hardly noticable. I could send a paper pattern if you think you need it.

Good luck.

 

[RedRamAndy]

Thanks James and WJune,

I just might go for the access-hole idea. I have an old '54 Chevy with that and it makes so much sense. I guess the factory was saving $ by not doing that. Heck, they pop-riveted the window regulators to the doors!

I have an assortment of body tools and welders and was thinking of using an abrasive-wheel cutoff tool to remove my panel without warping. Then weld a flange around it to refasten with a foam gasket. I don't readily have a donor cab around to cut an oversized panel from. A pattern would help a lot WJune, I'd appreciate that My truck needs new carpet anyway.

The transmission will come out over the winter to fix the rear engine main seal, but it would be nice to pop the top on the old Getrag to see what I need to start searching for. I just feel that there are a few problems here all stacking up and playing off each other. I really would like to peek in.

Thanks guys!

 

[RedRamAndy]

I finally got the truck licensed and am enjoying driving it. The transmission had made the loud random clicking sound I was told for the last 30,000 miles. Now with the thicker oil and 1qt overfill it is a steady light clicking as I mentioned earlier (see previous posts for details). I do plan on pulling this over the winter and doing an overhaul and new clutch, and new rear main seal. Most of my friends say if it's been making noise for 30k, just drive it and build it later.

Now to the punch: One bud of mine warns me of a locknut coming loose on the reverse gear that can just grenade the whole transmission in a blink. This has me paranoid. Is this true? I hate to stop driving my new toy, but might have to... .

Thanks for all your help folks!

 

[pepecat]

that's a new one on me... I would look into it further.

 

[1stgen4evr]

"locknut coming loose on the reverse gear that can just grenade "



Absolutely not!!!! That is in the NV4500 that some think is so much better than the Getrag.



Noises are not a good sign whether they have just started or whether someone thinks they have been going on for a long time. I would advise that you get to the bottom of it asap.



It would be just a guess but there might be a fractured tooth which could have the same result as mentioned on the 4500. I have two spare trucks so the decision is not the same for me but I WOULD NOT DRIVE IT ANOTHER DAY.



James

 

[RedRamAndy]

I'm going to try my best to make the time to cut the access plate in the floor, and try to quit driving it. I just have to convince the 'project priority police' in my house how serious this could be if it does let go. I will take the opportunity to power wash the grimy carpet as well. I have a few minor hauling jobs that are home-improvement related so maybe the truck's priority will be bumped up a bit, if you know what I mean The noise is not very load at all and barely audible when the transmission's warmed, but I need to find out what's doing it. I like the cheap-easy access hole method.

Wish me luck.

Thanks guys for clearing up the locknut issue, mistaken identity.

 

[RedRamAndy]

Getrag is OUT, Clutch bad, OilSeal questions..

I decided to patch this update onto my original thread:

I bought the 800lb rated Harbor Freight trans jack which did a nice job cradling the trans from my 2WD. I left the bellhousing on the motor for the pull due to clearance concerns getting the whole thing out from under the truck.

I figured out how to get the shifter stub out of the trans so it could slide back out of the bell. Any of you experienced guys humming 'Pop Goes the Weasel'? Well, I'm experienced now. . :-laf Glad my head wasn't over it!

transmission's now out and everything on it looks great. I can feel no bearing slack and minimal lash in the gears. If it wasn't for that rattling sound in neutral going away when I pushed the shifter, I'd say the trans is good. It's going to the rebuilder anyway. Probably new shift forks?

Next was the bellhouse pull and then the clutch. That is the biggest clutch I've ever seen (being a musclecar guy)! The throwout bearing is way-dry and rusty. Definitely rough. The pressure plate and flywheel were then pulled. They both look good with one tiny heatspot on each. The pilot is a bit galded, but not real bad. Then I started looking at the driven disc... . It seems the center splined hub, with the torque shock springs, is loose in the disc. The tabs that hold the springloaded hub are all broken off allowing this whole hub/spline assy to spin about 10 degrees fore and aft as the hub hits it's limit stops, rendering the springs useless. (See Pic) THIS is definitely the source of my excessive lash-slop that I heard when shifting, going on and off the throttle, and upon final shutdown with engine idling in neutral and clutch out. I'm surprise at how tiny these springs are in this stock Sachs clutch. They are smaller than the ones in my Neon.

I'm tempted to go with simply a new disc, since everything else looks good. I'm definitely getting a new throwout bearing and pilot. Should I get a roller pilot, or the big ball bearing style. I know machining is required for the ball, is it for the roller?

I'm doing the leaky rear mainseal as well. Advice on that? Do I really need to by the installation tool? I used a PVC pipe coupler as a drive tool for my rear grease seals and am tempted to do the same with this rear main.

 

[dpuckett]

The clutch disc wear can be the source of your noise in neutral- it was in mine. Disc was SHOT- springs all but falling out.



I would go with a ball bearing pilot, if for no other reason than it is sealed on both sides. Stock roller pilot bearing isnt. Flywheel will need bored for either.



I havent seen a Sachs clutch with springs that small, either. The ones I've pulled have had I think 5 or 6 springs, but they were almost as big as valve springs.



Daniel

 

[RedRamAndy]

I looked at that disc and missed part of the setup. It seems that little spring cluster is a sub-absorbing set of springs for harmonics. There are much larger springs enclosed in the metal 'humps' around the center of the disc too. These are the big boys.

Yep, I'm thinking this was most of my noise too. Thanks for the advice on the pilot. I noticed on Quad 4x4's site that the roller style is now double-sealed too. Just didn't know if it needed boring to fit. Thanks for clearing that up.

If I had the coin, I'd just buy the whole clutch assy from them with that ball pilot already installed.

C'mon Lotto... .

 

[RedRamAndy]

Final Update

The clutch disc with the broken springplate was 90 percent of the noise. Woo Hoo! I put in another disc and DA'd the flywheel and pressure plate, and buttoned it all back up (new pilot too). All I have now is a slight rattle once in awhile at idle. I think my truck idles too low too. This will be adjusted soon and all the noise will be gone.

BTW, put in a new rear mainseal from Cummins (included installation tool kit) and that worked flawlessly. I can park on the concrete now with not even a spot! Used to have a softball sized one in a few hours. That old seal was not even tight in the block. It was loose and spinning. I picked it out with a bent paperclip.

Happy camper whose $1000 transmission project went to $150 Oo.