Archived lost 5th

[CBloom]

help or advice 99 3500 5spd lost 5th has all other gears no noise or any commotion traveling on interstate at 62mph on cruise and it reved up then lost rpm kicked the accelrator but it just reved up put in 4th can runat any speed no noise or anything

 

[wcjp]

Friends 98' just did the same thing. He upgraded to rebuilt unit with the mainshaft upgrade. Two local quotes were $1800 and $2000 for the rebuilt only. Once the transmission was dropped it was discovered the clutch needed help. He stayed with the stock flywheel/Southbend clutch. If you're looking to stay with what you have a search will yield lots of info. At a minimum you'll need a new lock nut.

 

[CBloom]

what is the main shaft upgrade? got to a dealer tech was there that had the nut back off on fathers' 5spd said he just cleaned and locktite the thing then peen the nut and threads

 

[wcjp]

There have been many attempted fixes for the lock nut. Welding is another option I don't recommend. There are a few companies that have upgrade kits available. In addition to search on TDR here are three companies:



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[R C Cola]

5th Gear

Staking and/or thread chinking to stop nut coming off may work fine though I have not tried that. Many threads on this by the way. On mine I chose to use 2 small tack welds about 1/4 inch diameter across from each other. Small is the key word here, too large Will damage the shaft. Mine now have close to 200k of commercial pulling with no sign of a problem. I can tell you that many commercial drivers have had less than happy results from the factory suggested lock-nuts etc. If you read the threads you will see lots of dissaggrreement on this subject. Your decision, your bucks when it breaks. Best of LucK !

 

[CBloom]

repaired with locktite an many peened threads i had used the peen method on a lot of farm equipment in the past time will tell thanks to all who responded craig