I have 175k on the tranny, recently changed fluid. have always used redline fluid have put in extra qt. last 4 years. in the last month have noticed a straining sound when I engage into forward gears. same sound is heard when I down shift with higher rpm's. does not make this sound in reverse. it will not make the same sound as loud when I shift and the rpms (foot) is as hard. the sound reminds me of a a straining power steering groan. the DD clutch is new less than 20k miles on it. this sound cannot be heard in gear and driving only when I shift for the second after the gear is engaged. I dont know much about the 6 speed. what are the symptoms of the main shaft bearing. when I changed the fluid less than 5k miles ago there was nothing but normal small ammounts of brass. like it always has looked when I changed it. my tranny has always been notchy shifting alittle more when I put the DD in but have heard this is normal. thanks for the reply's

-Justin

 

Type "NV5600 repairs" in the address bar and start calling some search results or call http://www.4x4tools.com/top%2010%20tools.htm or http://standardtransmission.com/

 

I would do a little more investigating before you get carried away about a rebuild.

You say it makes the sound when you shift but does it make the sound after you shift and are just traveling down the road?

If it's only while you shift I would lean towards a bad throw out bearing. Was it replaced when you did the clutch?

Does it make the sound when the transfer case is engaged in 4wd?
Whens the last time you serviced the transfer case? Anything out of the ordinary come out in the drained oil?

For the few minutes it takes, pull the front shaft off and see if it does it.

The 5600 is a big iron pig and it does make some noise. I'm over 200,000 miles on mine and with regular oil changes like yourself. Other than the usual brass particles in the oil when I drain it, nothing out of the ordinary.

They don't shift like a car transmission so yes they are notchy and clunky but they will take some abuse.

Personally I would change the oil out to Amsoil MTF. I ran Redline for a little while and didn't like it. With the Amsoil, it shifts way smoother, runs cooler and just seems to run better overall.

Can't say much else without a little more info.

Jeff

 

By 'straining' do you mean a whining noise. THis may be your synchros catching up to mesh.

If your fluid was clean on the change and it will go into gear w/o feeling like you are gonna bend the shifter your probably ok.

May be something else like a throw out bearing, or worse a trans bearing, but this would sound off all the time.

 

thanks guys
yes the sound is only when shifting with heavy foot and shifting soft. as well as down shifting. the whine sound doesn't last but a second. doesn't do it while in gear and driving. the front shaft is off and still does it. I pulled it last weekend to see if it was the probley. the transfer case was just changed. I haven't tried it in 4wd yet to see if the sound is worse or goes away. I may look at amsoil. what oil from amsoil you using.
as far as I know the throw out was changed I think that is part of the DD kit from south bend. I will have to ask sourceautomotive they did the install for me almost a year ago. if I'm right a throw out bearing would only make sound when engaging and would stop once in gear if it was bad. as a pilot bearing would be quiet when clutch was pressed in and would be noisy when the truck was moving in gear if it was bad. thanks do some looking tomorrow. also may have to find out where amsoil is around me.
thanks again

 

I drove mine around the block last nite with no radio on and tried to mimick what you are having. Mine will whine a little when force downshifting, but I rarely do this since the rebuild. I just let things line up and she slides right in.

I also have more noise in N with the clutch out, than when in. But this has been the case since my new trans and clutch went in over two years ago.

 

Mine will do the same whirring noise. It's the synchros speeding up as your about to make a shift. And yes it also makes all kinds of "spinning" noise while idling in neutral.

As for the Amsoil, it's just Amsoil MTF

http://www.amsoil.com/storefront/mtf.aspx

Jeff

 

whats funny is I just recently took off the 6" stack and put on a 5 inch exhaust makes me wonder by making the exhaust quieter now without the stack I'm hearing sounds that have always been there. I will just watch the sound it seems to appear just prior to the clutch fully releasing and gear engaging. so it sounds normal.

 

HA HA! That's what I meant when I said I ran with the radio off. When I turn the key in the a.m. I can't believe how loud the radio is!

My trans does make a lot of noise though, more than a gasser's.

 

can anyone tell me what the symptom of a bad throw out bearing would be. how loud is this sound?