"imported" 80 apparently needs new gearset sent from Japan???

[Roach15]

Hi guys,

I've done a search and I can't find any info on this here, and it covers a few quite specific issues. Hope it's ok to start a new thread.

I'm quite a newbie with a wrench so please forgive any elementary comments etc.

The short story is I have a HDJ80 '94 (350k km, with the three factory lockers) which I bought in London and drove to Namibia, Africa (current location). I have had some local axle and gearbox specialists tell me that I need a new gearset, and furthermore it must be sent from Japan as my car is an "import" and therefore local parts won't fit. They have also said that the gear ratio is different so any gears elements along the whole drive train cannot be sourced locally. The gearset would take 3 weeks to arrive (I'm still travelling) and would cost approx USD 1,300. I'm looking for a cheaper and quicker solution to get it back to 4x4 without compromising long term quality. Photos of crown and pinion below.

My specific questions are:

1- Does this make sense? It sounds strange to me that Toyota would produce different gear ratios for trucks sent to Europe
2- The reason for the replacement is that the teeth on the ring and pinion have become worn and are on their way out due to a loose pinion nut. However, to me they look quite good, although apparently they've worn through the tough part of the metal and they're going to continue getting sharper and sharper until one completely gives out and creates a lot more issues within the diff. This could happen "within 50km or 1,000km". Does this sound correct? I would have thought that readjusting the preload and tightening a new pinion nut would solve the problem, but apparently not.
3 - If I were to reassemble everything and adjust the preload and tighten the pinion nut correctly, realistically is there any way to tell what the minimum mileage I can get is? Or am I just playing with fire? For the time being I've just got the pinion setup in without crown or axle shafts and driving 2WD with ctr diff locked.
4 - If I'm out of luck, does anyone have any alternative ideas on sourcing a pinion/crown quicker and cheaper to fit my truck? (ie equivalent parts that could be used 2nd hand (even whole diff), aftermarket products etc)
5 - A side question for whoever might know - The heater pipes which run along the chassis are cracked and leaking radiator fluid just under the driver's seat (RHD). Will there be any problems if I just block them off, or will it interrupt the water flow / damage the pump or anything?

More background info if needed:

- The ORIGINAL PROBLEM was identified with a slight whine consistent with speed but present only on acceleration / coast. There was also a worsening leak at the pinion seal, and slight up/down play at pinion bearing. The free spin twisting of pinion (all assembled) was about 3/4' but when dismantled the contact with crown was quite tight. Maybe 1mm of play. I have no idea what's normal.
- The FRONT DRIVESHAFT HAS BEEN OUT for some time (since the leak at pinion seal) and it currently rides smoothly with no noise as RWD only
- There were only very MINUSCULE METAL SHAVINGS in the drained diff fluid
- FRONT RIGHT CV has been leaking diff fluid for some time, although the seal was replaced just before commencing the trip. Started leaking almost straight away but there is a slight groove on axle shaft
- My VIN which was apparently used to determine the parts needed is JT111TJ8007018519.

Many huge thanks in advance for any advice you geniuses can come up with.

Cheers!

Phil

 

[OffGridOverland]

Gas or Diesel?

Also do you have a automatic or manual gear box?

 

[Roach15]

Oops rookie oversight. Manual 4.2L turbo Diesel

 

[sbman]

I think you might want to contact this guy: http://gearinstalls.com/ I think he's a forum member, and also seems to be an expert at toyota diffs. I was reading through his install logs on his website and was linked there somehow through MUD, but can't remember the name.

 

[Tools R Us]

...
3 - If I were to reassemble everything and adjust the preload and tighten the pinion nut correctly, realistically is there any way to tell what the minimum mileage I can get is? Or am I just playing with fire? For the time being I've just got the pinion setup in without crown or axle shafts and driving 2WD with ctr diff locked.
...

Just going from the pix and and little debris on the magnet, the gears look usable to me. I would assemble with new pinion bearings, using the same shims (can't really setup used gears), set the backlash and run it. Obviously it's impossible to predict life, but the same could be said for new gears? There is the possibility that they will make noise, but I wouldn't be worried about them making it back where a proper repair can more easily be made (if needed).

I have done this on several units, all are still running, got lucky none make noise and all are wheeled, big tires, etc.

 

[BigAxeJack]

Regarding your coolant hose question, the hoses you refer to run to the rear heater unit located beneath one of the front seats. I have heard of several cases where these were rusted/damaged/leaking and were blocked off without causing a problem. Best of luck in your travels!

 

[BILT4ME]

As I look at it, I am going to assume you are in a tight situation and need to have a vehicle that operates. If I was in a foreign country and needed to keep moving and it was going to be 3 weeks to get parts and there is a reasonable alternative, I would take the alternative.

When I look at that R&P (Ring and Pinion) it calculates to 3.73:1 ratio. That will be specific for that version and with a manual turbo diesel, it makes sense. Most of the North America units came with 4.11:1 ratios

If I needed to keep going, I would reinstall with new bearings, new seals, and new crush sleeve or re-use the block (if that what was in it) and have it re-set up with correct shims. The teeth are not chipped or ground out, and with good oil in the diff, it should run for a while. It may whine a little but nothing serious as long as you are not abusing it.

Have the birfields re-packed with good Moly grease, and the wheel bearings with good NLGI2 grease. Make sure you clean or re-route and install new breather vent hoses on your differentials (front and rear) to allow them to breathe with the temperature and elevation changes.

On the heater hoses: You can use a length of hose and re-route the heater hoses in the engine compartment to bypass the heater. Don't just block them off, re-route so the coolant can still circulate

Just differentials, the guy goes by the nickname "Zuk". Do a search for that and you will find him.

Good Luck in your travels.

 

[Howard705]

Look usable to me. can't tell in quick reading if it's front. Last forever in the front if only used when needed. OR change front and rear to 4.11:1

 

[Golgo13]

http://www.japan-parts.eu/toyota/eu...s/4101_rear-axle-housing-differential/3#41201

This shows a Gear Ratio of 3.727 for the R&P set.
41201-69245 is the PN for the set.
According to this: http://www.japan-parts.eu/?part=41201-69245&regi=EU&cars=ok
This seems like it was only used in Euro destinations for both Gas and Diesel as well as LHD and RHD vehicles.
I would think replacement parts have to be available somewhere, but maybe getting them in Namibia is an issue.
I have to imagine there are repair shops and off-road shops in both Namibia and South Africa which would have these in stock and could ship right away.

@gearinstalls.com
Ken, what do you think?

 

[ALX4X4]

In Australia, all the 1FZFE and 1H**** engines run 4.11. No difference, manual/auto, petrol/diesel, all diff ratios are the same at 4.11

 

[Tapage]

In Australia, all the 1FZFE and 1H**** engines run 4.11. No difference, manual/auto, petrol/diesel, all diff ratios are the same at 4.11

Same here .. share with us the trans axle info on the firewall plate.. if it have stock gears we can tell from there ..

 

[landtank]

Me personally, I'd load them and go. I think they look fine. If you can re-assemble without the crush sleeve and try and get a reading on pinon depth with the gear paint.

 

[Roach15]

Brilliant guys, thanks a lot. So paraphrasing I feel like this is the situation:

- It does indeed have a gear ratio unique to EU, so at some point it might make sense to change this to match local. @Tapage Transaxle code is K304. According to
http://www.off-road.com/trucks-4x4/tech/toyota-differential-identification-18588.html
It's a 9.5" crown and 3.737 ratio as @Golgo said.

- Reassembling the gears is an option and unlikely to risk severe damage to the diff (in the short term at least). This would be subject to checking the pinion depth with gear paint (if I can find some!). Are there any telltale symptoms to signify the last few kms of the diff? Should I periodically remove the bottom bung quickly and replace to check for larger fragments? Is the sound gonna get unbearable before things go seriously wrong? Before I removed the prop shaft it was only a hum, only noticeable because I've spent so long in that car.

- @BILT4ME I also would expect (from intuition rather than experience) that it would be better to reroute the heater hoses rather than block them off.

I'll drop Zuk a line - I also found his website very helpful in getting my head around what the inside of a diff looks like. I only learned that "third member" isn't a porno movie name a few days ago.

Look usable to me. can't tell in quick reading if it's front. Last forever in the front if only used when needed. OR change front and rear to 4.11:1

It's full time 4WD - I see the logic in that for lockable hubs / part time 4x4... Does it still hold for 4x4?

http://www.japan-parts.eu/toyota/eu...s/4101_rear-axle-housing-differential/3#41201

This shows a Gear Ratio of 3.727 for the R&P set.
41201-69245 is the PN for the set.
According to this: http://www.japan-parts.eu/?part=41201-69245&regi=EU&cars=ok
This seems like it was only used in Euro destinations for both Gas and Diesel as well as LHD and RHD vehicles.

fantastic! I didn't realise those catalogues were online. That is going to make parts ordering etc much easier in the future. Thanks.

 

[Roach15]

@BILT4ME forgot to say - the roads are actually pretty good down here now, and I don't need 4x4 to get from A to B. It just reduces my options for more interesting tracks and beach time. Perhaps I could reassemble everything and remove/replace the drive plates periodically (in a similar fashion to lockable hubs) as needed to preserve the life of the gearset? A bit of silicone around the hubcaps each time to keep dust out.... There are a lot of dirt roads here though.

 

[Howard705]

In 2 wheel drive there is virtually 0 load on the front diff compared to being locked in. If it were to get to a point where you are at the last kms of the diff (gears)- you'll know it -LOUD NOISE . Don't need to reset pinion depth-that's out with the wear and will return to where it should be with the new bearings. It will make some noise now with the wear on the teeth. FWIW I ran an old Chevy (part time but locked hubs in during winter) for years after ring gear bolts backed out-tearing up the gears some-a couple of the bolts even went through the teeth taking parts of them out. I replaced the bolts and was fine.

 

[gearinstalls.com]

Hi Phil-
I agree with the others in that the ring/pinion is probably just fine. Pinion depth is just fine so don't disturb that. It would be nice if new bearings/seal/nut/crush were available but there are other options.....It's the outer pinion bearing that should be visually inspected. It should be replaced but if it looks like no chunking is occurring and you can't source a new one then it can be re-used.
What parts can you get, Phil? Can you source the 4 bearings? If it's not possible then it's still very possible to take it apart....new seal.....snug pinion nut until you get a small amount of bearing drag.....put the carrier(the part with the ring gear bolted to it) back on. Snug the adjusters and adjust for about .2mm backlash. Done. I can help walk you thru the procedure as you do it. Ken

 

[Photoman]

Too late now, but in the future the way to check what the gear ratio is; just count the ring and pinion teeth and do the math. From the OP's pictures, 11 pinion 41 ring. 41/11=3.727272...
Old school when we knew what ratios were available was to put a mark on the driveshaft and count the turns to make the wheel go around 1 rotation. In the OP's case it would have been about 3 3/4. If it was a little over 4 then 4:11.

 

[Tools R Us]

... This would be subject to checking the pinion depth with gear paint (if I can find some!).

I wouldn't mess with it. The gears are broken in at the setup, shim(s) that it has, changing it wont be beneficial to the used gears. The paint pattern is difficult to read on used gears (especially when they have been run with bad bearings) depending on the experience of the installer, may cause more issues than it will solve. Best to just install with the original shims and set backlash to spec.

... Are there any telltale symptoms to signify the last few kms of the diff? Should I periodically remove the bottom bung quickly and replace to check for larger fragments?

Whenever this type of work is done, would change the gear oil after 500mi or so. This will flush out any debris from having it apart and give an idea of condition.

 

[scottryana]

Let's us know if you find the 3.72:1 gears available somewhere, would be interesting to see how much they are. Might be some cummins swap guys that are interested.

 

[Roach15]

Thanks guys! Hope you all had a cracker of a weekend.

@scottyryana the only source for the gearset so far is ex-Japan at a retail cost of approx $1,200. Still phoning around to find other options though.

What parts can you get, Phil? Can you source the 4 bearings? If it's not possible then it's still very possible to take it apart....new seal.....snug pinion nut until you get a small amount of bearing drag.....put the carrier(the part with the ring gear bolted to it) back on. Snug the adjusters and adjust for about .2mm backlash. Done. I can help walk you thru the procedure as you do it. Ken

Hi Ken,

Thanks a lot, much appreciated. Actually, I think I should be able to get most of the parts except the gearset. Getting a few quotes today and should have them in the next couple of days. I was told that when new bearings are installed that the preload and everything must be readjusted, is that correct? Would it not be possible to set the preload with a scale and vice? I will give it a go but I might send you a message if I get stuck - thanks for the offer!

From reading around and looking at the gears, it seems the backlash is set by adjusting the position of the ring by turning the large nuts outside of the bearings by an equal amount and in the opposite direction. Is there anything else to look out for?

I also have slight grooves in the axle shafts which I think caused an oil leak on one side straight after the last CV job. The other side held up but also has a slight groove. I figure I should get both redone - any reason not to? I think the engineering guys here can either weld and smoothen over the top or put a sleeve over.

@toolsrus - that sounds like good advice, I'll do that for sure. Any idea what the spec would be or where I could find it? Seems like 0.2mm?

Cheers!

Phil