Getrag and stock clutch

[J DeMaio]

Hi guys:

I was wondering how the Getrag and the stock clutch hold up with a slightly modified Cummins. Peter from SBC thought the clutch would hold ~300. My clutch seems to be doing great. The catch point is very low, it probably catches with the pedal 1/4th of the way up.



My future mods are: 16cm turbo housing, new exhaust, fuel tweak, maybe new injectors. I would probably be at about 200 horsepower without the injectors. I don't tow but if the need ever occured I wouldn't want to ruin the clutch.



Now, How does the Getrag hold up to the added power?



Thanks,

 

[Lil' Dog]

My '89 has had over 200 hp for a few years and the transmission seems OK. Small input shaft leak but no grind or growl. With the mods on the 89 I was running around 24# boost so approx 240 Hp. That transmission is original.

 

[19Kgvw]

Hi, I've got a '93 with turned up pump and big injectors. Probably 220-230 hp. I tow 10k to 14K lbs. nearly all the time with the stock set up and haven't had any slippage even over the mountain passes in the Northwest. My truck has 103k miles. I have the additional filter available from Genos on the transmission and put in synthectic 5-30 wt oil..... I change the oil every 10k miles, figure that it's cheap insurance, don't want to lose my Getrag. My clutch also engages at approx 1/4 of the way up.



Sometimes I get a "growl" out of the drivetrain (don't know where, clutch assembly?) just when I'm engaging the clutch. I plan on replacing the pilot bushing, TO bearing and clutch soon just so I am not worrying about it.

 

[South Bend Clutch]

19KGVW,





The growl that you here on engagement of the clutch is most likely your pilot brg. When the pilot brg. gets worn it allows the input shaft to oscillate on engagement inside the pilot brg. The damage that occurs if this continues is, ware to the dampened disc center and front bearings of the trans. along with the front seal of the trans.



Peter

 

[Scot]

Originally posted by South Bend Clutch

19KGVW,





The growl that you here on engagement of the clutch is most likely your pilot brg. When the pilot brg. gets worn it allows the input shaft to oscillate on engagement inside the pilot brg. The damage that occurs if this continues is, ware to the dampened disc center and front bearings of the trans. along with the front seal of the trans.



Peter

Mine never did growl since I bought it at ~70K miles. The throwout bearing started howling at ~135K miles. When I pulled it the input shaft bearing was shot and resulted in a 0. 100" musharoom on the end of the shaft. I am sure glad I can do my own work!

 

[JFitzgerald]

Mine makes a bit of noise when letting the clutch pedal out. Just got the truck, so I wasn't sure if it was normal or what. Maybe I should have someone familiar drive it and tell me if I need to tear it down. It has 106K miles.



I too am curious about how the clutch and trans will hold up to future power upgrades.

 

[Bob Beauchaine]

Hi J DeMiao

My getrag decided to go south at about 120,000 miles. It would grind going into 3rd & 4th so I had it rebuilt. To make a long story short I finally gave up on it and put in an NV4500HD - for which there is a fix (5th gear nut). My original clutch was in very good condition and gave me no problems.

The NV4500HD is a much guieter and easier shifting trans. I can pull 70mph in 4th and all I hear is the sweet sound of that Cummins hummin. The Getrag would drive you out of the cab at 55. Look at my signature for upgrades. I will dyno my '93 in the near future to find out what she is putting out.

BTW I've got a rebuilt Gertag with about 1500 miles on it if anyone is interested.

 

[Scot]

My clutch still had probably 50K miles atleast on it when i pulled it at 135K. I bought all of my parts from Standard Transmission in Ft Worth TX.



Several here have said the Sachs clutch is actually a lot more clutch than is necessary for this application. My thought was to just replace the disk and not the cover. It is an 13"(?) disk and pretty much only available from the dealer. Yea ouch! STD Trans sold me a replacement 12 1/2"(?) LUK clutch kit (new) for a reasonable cost. I no longer have any partial release hop like the Sachs had.



As for the Gutrag, drive it easy if you pull and it might hold together. If you decide to upgrade to the NV4500, STD Trans has a kit with all you need and it already has the fifth gear fix done.



Sad part is, when I tore my Gutrag apart, it is plainly obvious why they shell so easy. The thrust is held by washers retained by a relatively thin output housing. Ten years ago, I could have made a mint selling a heavy output shaft housing/truss.

 

[JFitzgerald]

I noticed the clutch hop thing when backing my trailer this weekend. That is annoying. So, the stock clutch is a "Sachs"? What should a clutch kit, throwout and pilot bearings cost me for my truck? I see TST has a clutch, is it worth it? I will be towing/hauling up to about 9,000lbs.



The Getrag is not the best shifting trans, but mine seems to be quiet and happy for now. The previous owner used a special gear oil additive that he got from work. He claimed it cut breakdowns in gearboxes at his factory to less than half what it was.



If my truck were 2WD, I would not be happy with the first gear ratio. I am used to the old GM 4 speeds with the 6. 55 (SM465) or 7. 05 (SM420) first gears. At least I have low range in the transfer case.



Another question : Can the Getrag hold up to shifting without the clutch? With the old GM 4 speeds, it never has caused a problem for me.



Thanks guys.

 

[Scot]

The clutch kit from STD Trans (1-800-783-8726) was $235 +tax (no core). That is cover, disk and throwout bearing. Pilot bearing is $3. 99. I wound up having to also buy the input shaft at $200 and the large input shaft bearing and seal.



From what I can tell, there are only a few companies that actually stamp clutch parts. They are bought by the clutch makers and built in their own special way.



When you drop that SACHS out be ready. That sucker must weigh 50 lbs!



I am not sure if I have had quite 9K since installation but the clutch seems great at ~7500.



As for using the clutch, my vote is yes since the transmission is marginal at best.

 

[KEENO]

An Appology to SBC...

First Off, an appology to South Bend Clutch.



I have mentioned on this board my irritation w/ neutral disk rattle on my newly installed (in February) SBC consisting of a Luk Pressure Plate, Valeo Clutch Disk, special self centering Throw Out Bearing (ask SBC) and Kevlar Pilot Bushing Kit purchased for $450. 00 including shipping from Woody @ SBC.



I recently had installed a NVG4500HD Transmission by Quad 4x4 in Roberts, MT. and now the "Disk Rattle" has mysteriously disappeared. It now seems that it might of been the old Getrag rattling and not the Valeo Clutch Disk.



I agree w/ the statement that the OEM Sachs might be too much clutch for our application and have enjoyed every other aspect of the SBC Package (engagement, driveability & holding pressure) over the Sachs and not having to deal w/ the 'jerking' while in reverse. I now feel that the SBC kit I have installed is an excellent clutch choice when the time comes for replacement.



With my "Clutch Disk Rattle" resolved by a new trans I sincerely appologize for mentioning that my SBC Clutch use to "Rattle like a spoon stuck in a garbage disposal" while in neutral.



Keeno

 

[South Bend Clutch]

Keeno,



I would personally like to thank you for the apology. Not too many people would have the guts to repost something that they have found to be in error of their earlier post, especially when tempers were raised. It takes a good person to do what you did.



I'm glad the clutch is now working good for you. We hope it continues.



Peter

 

[Cummnzpowr]

Stock clutch,stock Getrag transmission here... ... pump tweaked by piers, full power screw turned up to 5 turns..... 39 lbs of boost in 5th gear full throttle... . PWinjectors. . 12cm housing... custom intake... . clutch slips a little around corners if i floor it, {so do the tires,so}... but otherwise normal getrag growl in 4th and 5th under full throttle {lower RPM'S} ... leaking a little oil i think from rear main seal, but it still purrs... ...