A few general NP435 questions ...

[smclaren]

Hi Guys

Just a few general NP435 questions if anyone wants to quell my curiosity.

- General impression about the box. Reliability, Serviceability etc etc. Also, the story with the PTO plate ?? Anyone use that stuff ?? If yes, what for ?? Looks too hard to get at to be usefull??
- Mine leaks a fair bit. Is this common ? What generally are the seals/gaskets to replace to tighten them up ?
- Mine grinds intermittently when dropping back from 4th to 3rd. I still can't quite put my finger on what trigers it (speed, rev's, cornering etc) I am guessing that the syncro is on the way out or is there a common issue here.
- Has a classic gearbox rattle under load at low speed in 3rd dissapearing when speed and rev's are acheived ... is this common ?
- I need to replace the clutch plate in my truck soon ... so I am thinking on an overhaul on the tranny. Are they a quick and easy overhaul (this will be done by the pro's, not me) ? Any tips here ?

Any user/abuser/repairer/dispairer comments and general tips greatly appreciated.

Steve

[Redcap]

Hi Guys

Just a few general NP435 questions if anyone wants to quell my curiosity.

- General impression about the box. Reliability, Serviceability etc etc. Also, the story with the PTO plate ?? Anyone use that stuff ?? If yes, what for ?? Looks too hard to get at to be usefull??
- Mine leaks a fair bit. Is this common ? What generally are the seals/gaskets to replace to tighten them up ?
- Mine grinds intermittently when dropping back from 4th to 3rd. I still can't quite put my finger on what trigers it (speed, rev's, cornering etc) I am guessing that the syncro is on the way out or is there a common issue here.
- Has a classic gearbox rattle under load at low speed in 3rd dissapearing when speed and rev's are acheived ... is this common ?
- I need to replace the clutch plate in my truck soon ... so I am thinking on an overhaul on the tranny. Are they a quick and easy overhaul (this will be done by the pro's, not me) ? Any tips here ?

Any user/abuser/repairer/dispairer comments and general tips greatly appreciated.

Steve

I can't answer all your questions, but...

The 435 is a real stout, reliable transmission. The PTO output is real useful if you have a PTO winch or need to power a hydraulic pump for a dumpbox or towing stinger. Don't know how common the leaking is, but I know mine doesn't leak a bit...that's the oilpan on my truck. ( ) The gear crash from 4-3 is definitely the synchro....soon it'll growl when going from 2-3 if you shift too fast, just like the trans in my '67. Just double-clutch when you do the 4-3 shift.

Hope this helps.

[xxxtina63]

Tough as nails and they're supposed to be relatively easy to rebuild. Parts are plentiful and affordable, at least in the US.

[averagef250]

The 435 is an excersise is simple ruggedness. They have very few parts inside, the early new process synchros are built to last 3 lifetimes if you aren't an idiot and they generally last forever.

They have a reputation for being indestructible. For the small size of the components inside and the fact the mainshaft gears don't have bearings, they hold up amazingly well. You really have to beat on one with real big block power to break one.

There are only two seals in them. Replacing the seals will fix your leaks if the bearings are good.

[RedneckTexan]

I have a PTO on mine and I've had no trouble with it. I too have a question, When I shift from 2-to-1 (and the truck is still rolling), It won't go into 1, the gears grind 'till the truck comes to a totally complete stop. Is that normal?

[Redcap]

I have a PTO on mine and I've had no trouble with it. I too have a question, When I shift from 2-to-1 (and the truck is still rolling), It won't go into 1, the gears grind 'till the truck comes to a totally complete stop. Is that normal?

Yes, completely normal. First is non-synchronized. Why would you try to shift into first while rolling anyway? Second is all you need. I only use first gear when starting out pulling a HEAVY trailer full of stuff...

[Chaseman]

I have a PTO on mine and I've had no trouble with it. I too have a question, When I shift from 2-to-1 (and the truck is still rolling), It won't go into 1, the gears grind 'till the truck comes to a totally complete stop. Is that normal?

Do you mean first as in 2nd or 1st as in low cause until I slow
(5-9 maybe 10 mph) down it's hard for me to get into 2nd.

[19674x4]

there is no "low" gear, it has 4 gears with the first being a granny gear. just most of us use 2nd as out first. so essentially your only shifting a three speed.

[averagef250]

The 435 is a 4 speed, best not to call 2nd 1st because you start out in that gear, that just confuses everybody.

You guys ever notice how nothing else out there shifts like an old new process tranny? They have a definite preference towards slow shifting and shift like glass when you use engine RPM and don't use the clutch. The way the old NP synchros are made makes them work this way. The synchros are spring loaded and if you try to force a shift the synchro deflects and it grinds.

Don't crash a 435 into 1st or reverse while you're rolling. These gears are not synchro'd and they are such a low ratio that the difference between cluster and output shaft speed is huge even at just 5 MPH unless you have the engine idling at 4000 RPM.

[19674x4]

yea mine shifts very smooth when i dont use a clutch, most of the time thats how i shift it anyways. saves my clutch and it is almost a smoother shift. I cant even get it into first while rolling, i have to be a complete stop.

[Underdog97]

I wouldn't trade an NP 435 for a Warner ever. Granny gear is just that, she'll lug you up a hill or out of a mud hole every time, just not very fast. easy to rebuild and reliable. It's only downfall is that it's a heavy old girl and she's hard to manhandle in and out at clutch time.

[RedneckTexan]

I wouldn't trade an NP 435 for a Warner ever. Granny gear is just that, she'll lug you up a hill or out of a mud hole every time, just not very fast. easy to rebuild and reliable. It's only downfall is that it's a heavy old girl and she's hard to manhandle in and out at clutch time.

to everything above!

[Chaseman]

Shifting without using the clutch?.....

[19674x4]

basically you use the engine rpms' to match that of the drivetrain and shift when they match, thus not using the clutch. often called speed shifting or "floating the gears"

[averagef250]

Shifting without using the clutch?.....

All the clutch does is disengage the engine from driving the transmission input and cluster gears. The cluster gears drive the mainshaft gears and sliders on the mainshaft engage and disengage gears when acted on by the shift forks via the shifter and you.

The only purpose of synchros is to match the speeds of the mainshaft and cluster gears so the teeth can mesh. If you use the throttle to match cluster and mainshaft speeds for the gear you want it'll slip right in, no clutch needed.

You can't really get moving without the clutch or starting it in gear, but you can go through 2-3-4 and back down 4-3-2 fairly easily with an old 435. Just don't try to force it if it grinds, you are hurting the gears if you grind it.