hi,i just bought a 1994 f-150 manual floor shift 4x4,5 spd trans,220000 kliks.
thing is its quite noisy in 3rd 4th and 5th,a really pronounced humming that seems to be coming from transmission, also noisier in 4x4 mode.now will changing my transfercase and trans fluid to a thicker weight make it less noisy?or is this not going to make a difference?and will it hurt anything going heavier fluid?thnx for any help.

 

Unfortunately its prolly too late for just a fluid change if you can hear it like that. have you checked the level in both your transmission and you transfer case?

 

yes iv checked both,they are topped up,with an amber colored fluid, but my last truck,a1990 had red fluid in the trans and case.should it be the automatic type fluid in my 94?

 

The five speed manuals that came in these trucks all seemed to make a little growling noise. A certain amount of it is normal, when warmed up the ZF (rebuilt) in my 96 F150 makes a little bit of clatter. IIRC the shop manual actually calls for a synthetic ATF lubricant. I am running D/M ATF in my truck with a couple quarts of Lucas oil stabilizer in the trans and a half a quart in the t-case. I suppose you could go to a Type F ATF, it is a bit thicker.
John

 

incorrect info. Inserts foot into mouth

 

The thing with overdrive gearing is that when it's in overdrive, everything spins much faster to cause that reduction. This expedites bearing wear, and that causes pre-load to occur.

 

Are you getting noise in 1st or 2nd? I might be a little outside the box here but it could be your pilot bering/throw out bering if you hear noise in all gears.

At this late in the game (225K) you need to look at dropping the tranny and finding the problem. Adding thicker fluid will only mask the sound and not fix the problem (ie: bandaide on a bullet wound). Is this a DD? If you can deal with it being out of comission I would drop the tranny, replace rear main, pilot bering, clutch, slave cyl, and fix the M50D problems (or replace with a good ZF) and put it all back together. If you go that route you'll be doing yourself a big service eliminating future problems and this one in 1 shot...

Just my 2 cents.

 

actully it sounds great in 1st and 2nd its just 3rd 4th and 5th that the humming starts,or well it sounds like im in an old antique unit with 4x4 engaged.can you tell if its the throw out bearing by sitting in nuetral and pushing clutch in and out?no noise at all when doing this.i got a feeling i will be replacing the tranny every thing else is good,motor purrs like a kitten,(4.9 inline 6)but the truck really hops in 4x4 when turning,is that normal?my older 4x4s used to do that also.thanks for the help everybody,greatly appreciated.

 

You'd be surprised what you can replace yourself without tranny tools on that M50D. If you are going to replace it I would do ZF swap to the HD tranny from a f250-f350 of the same vintage (87-96). pilot bering will make noise at all times. Throw out bering will make noise w'out clutch in (i think)... either way it sounds like you have an internal transmission problem. Ask around at local parts store to see if anyone knows a tranny mechanic that does work on the side. they could inspect it and give you a estimate after you pull it yourself... If it's to much $$$ to save it you might want to look into the HD ZF I mentioned above. it's pretty much a bolt in and it's TONS stronger. I'm not a tranny mechanic at all!!! I know a Ford Tranny Mech and he does all my work on the side for me.

I don't have any hopping problems with my 88 F250 with 4.9 5spd zf. Don't know what would be causing that.

 

i would put a few quarts of lucas in there before i junked the tranny. i'd run 50% (or more) lucas/atf and run it til it dies.

 

just remember if it dies a long way from home you're screwed!

Honestly I dont like the M50D. Just look above... 89F2urd is doing a ZF swap right now, as he tells you in the same breath to keep the M50D he's getting rid of... LOL

Yeah run some Lucas but stay close to home and get a ZF ready to replace that old M50D!

 

i bought a zf cuz my m5od blew up. . . .after 280,000 miles and 10,000 reverse to 1st rips rockin out of mud holes. i ran it til it blew. . . .im basically promoting the very policy i exercised for myself. . .

the mazda trans, comparably, is not a strong tranny. but, these low power trucks dont have enough grunt to break them from power alone. rock it til it breaks, find a donor in the mean time.

 

Dude I'm all in on blowin the tranny and then swapping it... But some circumstances change this policy though... If this is your low buc DD then I would find a tranny and do the swap sooner rather than later. Also if you are using it for a work rig (ie: thumper is a wood hauler) a ZF might be better sooner rather than later.

Shane,
I don't know how you use your truck but I can speak from personal experiance that you don't want to be stuck somewhere without help to get home. I myself blew a M50D in the 92 F150 I used to have when it was loaded with wood and had a trailer loaded with wood right behind it. I knew the tranny was bad but thougth it would make it home... Didn't make it out of the field and I was 75miles from home and my friends with trucks weren't coming to pull me out since they were away at school... I guess my point is to understand your situation and do what's best for you... If you mud with 3-4 other trucks and can get hauled home... go ahead an blow that 5spd. If you can't afford a ZF or a rebuild you might want to find a tranny mechanic that will fix your M50D on his spare time (cheaper and you still get quality repair work). Ask at your local parts stores chances are someone knows a tranny mech that will moonlight for a little extra cash.