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My favorite piece...



And some others...



Click image for larger view.

Looking over the exploded view, I don't see anything other than the brgs' ball spacer pieces that could be that thin. And because we know that that's the weak area in this trans . . .

Is it just me, or does the piece I'm holding look like it passed between two gears?

There's damned little clearance between gears, so if it really did go through, it'd be thinner, I'd think.

But how else would it become so mangled? Fortunately, the gear teeth are a lot harder than the ball spacer material. But trying to stretch/compress metal between gears puts that much more stress on the shafts' brgs.

Vicious, isn't it?

Joining the club . The truck has 156K. Some noise started to come from the transmission. It's discrete, but definite. I can hear it at lower speeds. Decided to drain the transmission fluid, but didn't get too far. Started with the braker bar, but the plug is frozen.

Any tricks? I don't have air tools.

Tried with a foot long braker bar + pipe, but stopped because it was obvious that I am going to destroy the braker bar before the plug would move an iota.

2. HOW DO YOU REFILL THE TRANS? I don't see any refill tube for the transmission.

Zoltan wrote:Tried with a foot long braker bar + pipe, but stopped because it was obvious that I am going to destroy the braker bar before the plug would move an iota.

Acquire a better breaker bar.

From the factory, they use a sealant on the plug's threads that is particularly hard to break loose. If you can get enough torque on it, it'll move. However, the usual problem is to break it loose without mangling the square drive in the plug. Be assiduous about cleaning out that recessed square hole with a small, pointy tool, and remove all traces of dirt etc. before leaning on the bar. The plug is special -- besides having a magnet on it -- and you'll have to order it if you damage it.

Also, if the square drive strips, you'll have a real hard time getting the plug out, in any fashion.

2. HOW DO YOU REFILL THE TRANS? I don't see any refill tube for the transmission.

Not a tube, but another, similar plug on the driver's side, about halfway up the case. It has an external square part that you can put an appropriate wrench on. You can see it in this pic (click image for larger):



You'll want a gear oil pump to get the oil "uphill". The least cost for the least mess is a $12 Sta-Lube pump, but if you ask for a gear oil pump at any auto parts store, they'll have something similar.

If you're really, really cheap, and don't mind a mess, you can use a long piece of hose, one end in the filler hole, and run the hose up to the engine compartment, other end of hose on the pointy gear oil bottle adapter, or small funnel. You will have a puddle when you're done, but the trans will get filled.

Since I use synthetic gear oil that's typically near $20/quart, I don't like to spill.

Tip: buy a can of aerosol brake cleaner and use it's nozzle/wand to spray up through the drain plug all around and knock more cruddy oil down. And let it drain a good long while, like hours or more.

asavage wrote:SNIP- If you're really, really cheap, and don't mind a mess, you can use a long piece of hose, one end in the filler hole, and run the hose up to the engine compartment, other end of hose on the pointy gear oil bottle adapter, or small funnel. You will have a puddle when you're done, but the trans will get filled.

I'm cheap Here's my "filler". Funnel with 30+" of 5/8" heater hose. Just thread the hose from alongside the steering colum, down OVER the torsion bar, and push into the filler hole about 1-1/2". Allow a couple of minutes for the last little bit of oil to enter the gear box. But do have a pan under the trans when you withdraw as there will be an ounce or two remaining. Takes 2 quarts to refill. I'm using Royal Purple synthetic 75w-90 at $11 per quart.

My drain plug was in REAL TIGHT. The top of the plug was flush with the transmission housing. I don't install it THAT tight anymore. The square drive filler plug was also VERY tight and again, I don't install it THAT tight anymore.

I bought a gear lube pump from Walmart. It was intended for outboard motor use, but it doesn't seem to mind Nissan use. Best $8 dollars I've spent lately. Enough so that I bought a spare after I used it.

Gentlemen,

I drained the oil and what came out looked like colloid gold... The magnetic plug looked like a metallic kiddy cone ... + bearing basket debris like Matt's picture but perhaps even more. I recognized 3 rivets among the pieces


I called a few transmission places, one guy would only work with dealer parts and asks $1200 for replacing all the bearings. I'm still on the fence wether I should attempt to do this myself or farm it out. Especially that I don't know a trusty machine shop close by if I get stuck with pulling parts apart.

Al, the kit you purchased from the online store looks it has Japanese bearings, are they OEM? The full set of BCA bearings come out around $145 from partsamerica.com, and the gaskets would be extra. I don't know if I should trust the Japanese or American made more.

I'd be interested in what part were replaced in Philips trans and how much it cost him. My truck makes almost identical noises to his description.

Zoltan wrote:Gentlemen, SNIP

I'd be interested in what part were replaced in Philips trans and how much it cost him. My truck makes almost identical noises to his description.

I have shop connections so for a walk-in stranger, $1000-1200 for the whole job including a new clutch would be what I'd expect. Of course, there are Hawaii prices(?)

All bearings, gaskets, synchros were replaced and the trans has worked fine (has chatter noise) for 45k miles. That's the good news.

Now for the bad news. Once the gear wear pattern has set up, you will likely continue to have the "neutral/clutch out/chatter when hot" noise from the gearbox. This noise can be quite raucus on hot days and/or with thinner gear oil. Or you can get the entire gear cluster from a used box whose bearings have not yet failed and was still quiet. "New" gear sets are not cheap.

Whomever you choose to do the work, make SURE you both have a clear understanding about gear chatter after the work is done. If some shop promises there will be no more chatter after the rebuild, HOLD THEM to that statement. Get it in writing especially if paying a premium price.

Zoltan wrote:Al, the kit you purchased from the online store looks it has Japanese bearings, are they OEM? The full set of BCA bearings come out around $145 from partsamerica.com . . .

I didn't buy any parts from an online supplier, though I may have referenced drivetrain.com .

I bought the brgs individually. Upthread, I wrote:

BCA 205 $26.64
BCA 306-LO $71.02
BCA 204 13.40
NTN 63/22 $90
Extension housing bushing $16

This was not all of the brgs in the transmission, there are two that I didn't replace because I did not want to disassemble the cluster that far. The two brgs I didn't change are the centre support brgs, very std ones (6305, 6306) that are not expensive, except for the special puller/presswork to get to them. They are not the "ones that go bad". A comprehensive rebuild would replace them, of course, but I didn't replace the synchronizers either -- I was using a donor gasser gearset that was in quite good condition.

So I just changed my transmission oil last Friday and I found a whole bunch of metal on the magnet too. I got the truck last december, and judging by the rusted drain plug, I don't know if it was EVER changed.

My truck has about 187K on it and I need it to keep running for a lot longer. There sound in the transmission is, like mentioned above, louder in lower gears - but several people tell me it sounds ok, like the sound of an old transmission accepting load when you let off the gas. It sounds like grinding to me though - or maybe not in first and second gear.grinding, but definately FRICTION.

My question is, should I get this checked out now or just keep driving and not worry about it til things much worse? What's the threshold for this type of repair?

The other question is: when I was changing my center bearing I very stupidly jacked the front of the truck up a little bit and a red liquid came out of the tube where the propeller shaft goes into the transmission. What the hell is that? At first I thought someone might have put automatic trans oil in the transmission, but the trans oil I drained is dirty gear oil and not red. Is there another cavity in there ? - I don't know a whole lot about how the transmission and clutch interact either.

Thanks for the help,
Clayton

claybodie wrote:There sound in the transmission is, like mentioned above, louder in lower gears - but several people tell me it sounds ok, like the sound of an old transmission accepting load when you let off the gas. It sounds like grinding to me though - or maybe not in first and second gear.grinding, but definately FRICTION.

My question is, should I get this checked out now or just keep driving and not worry about it til things much worse?

If you have noise, the front bearing(s) is bad. You've seen the pics Philip & I have taken of ours, upthread.

If you don't want to try to keep this trans working a long time, just put new oil in it and drive it.

If you don't want to obtain a different transmission for replacement, pull that trans ASAP and replace the input shaft brg and forward countershaft brg. Though it looks like you could replace them from the front, it really can't be done that way: you have to split the case. It's not hard, other than all the cleaning you have to do before you split the case. Cleaning the outside of the my trans was nearly the hardest part of the job. On assy, you have to have oil-free surfaces to glue the case bits together. Be prepared to remove all the oil before applying the sealant. You'll need one gasket for the brg cover in front, it's cheap.

As you keep driving it with the bad bearing, the gears wear much faster than normal. Then when you try to replace the bad brgs, the gears are still noisy, and you've worn through the parkerizing or whatever.

The other question is: when I was changing my center bearing I very stupidly jacked the front of the truck up a little bit and a red liquid came out of the tube where the propeller shaft goes into the transmission. What the hell is that? At first I thought someone might have put automatic trans oil in the transmission, but the trans oil I drained is dirty gear oil and not red.

I've no idea on this one. Are you sure it was oil and not rusty water?

Is there another cavity in there ?

No.

So I finally got to the trans. Might have gotten to it sooner but I was soo dreading the mess. It really wasn't bad.

Mine's got 265k and the truck was down for work on the motor, but I remembered that it was starting to slip out of 5th when I'd back out of it. Nothing else. But after learning about the weak points of this trans I though I better look into it.

I would think that someone had been through this thing before I got it because it looks wonderful! I can't tell the old seals from the new. Except that the bearings are all original numbers, and I can't see any evidence of anyone having touched anything. I don't know, just happy it looks so good.

Anyway, reverse idler's a bit chewed up, probably from impatience in changing directions (it not being synched). Rear CS bearing looks ok except for what looks like a recently broken cage, probably shock from going into reverse. Be gentle putting it in reverse! If you look carefully you can see a big chip in one of the teeth. That's the little gear to the right, for the uninitiated.



The rest of the bearings look very serviceable, the two in the middle (6305, 6) looking the best. All clearances good except 5th, which was over twice the max (.028"), a result of wear between the mainshaft nut and the thrust washer.



The rest looks new. Can this be happening to me?

Just followed the instructions in the manual. Everything was a very light press fit. Had to put the whole cluster in the press to get the rear MS bearing off, barely fit. It felt perfect and I didn't want to damage it, otherwise I might have just hammered it off. No particular tools needed for the job. Uh, better have a stiff pair of snap ring pliers for that reverse idler.

Going to replace the bearings anyway. Glad I didn't wait. And glad I decided to do it myself.



UPDATE

Got a kit from Autozone for $125, two day wait. All Nachi bearings.



I was washing the needle bearings for 5th gear when one fell out and wouldn't go back in. Looking closer all the rollers were flat on one side, calling for further inspection. Looks like the rollers got jammed by some speck of metal, stuck in the gear and did some damage.



I ordered a new bushing and bearings for $60 from Nissan. Excuse me, the bushing was $30 and one needle bearing (of two) was $30. Lucky only one was bad. A new overdrive gear is about $250, so I just fired up the Sunnen and honed out .004" to clean it up instead. Found the $80 price for the reverse idler gear just like Al said, so I think I'll do what he did, after smoothing off the rough edges.

With less abuse and a couple of oil changes this thing probably would have done fine for a couple hundred k more.

Has anyone removed the striking lever from the shifting rod? The book shows what it calls a "lock pin" that looks like a tapered bolt. I can't get the thing out and if I had an idea of what it actually looked like apart I might do better.