1990 Ford Super Duty with ZF5 manual transmission SMOKING from shift boot!

[forhire]

After ruling out low fluid, a mechanic friend said the issue is likely on the output side. So this afternoon I went ahead and pulled everything out of the case to take a look. The assembly fixture I was waiting on made easy work of this task. Easier than I expected. Honestly worth every penny and I haven't even started the re-assembly. Simply tip it over and pull off the housing. Everything is then visible for inspection and you can feel everything in place. The output end bearing cup of the carrier shaft doesn't look good and 5th gear appears to have been getting hot. The 5th gear rollers feel smooth but there is a lot of play. My friend said he'd swing by my shop on Monday or Tuesday and take a look. I'm still waiting on my rebuild kit.





Does anyone know how the brake drum assembly is lubricated? I had assumed it was fed by the main transmission but I don't see any oil passages and nothing drained out of it. Does it have a seperate filler like a transfer case? I guess I better do some more reading.

[Freebirdwelds]

Love it when someone follows up.

[forhire]

I found the filler. It's above the vent. It's filled with Mercon, same as the transmission. I'm thinking it may be wise to service this unit.

UPDATE: I just pulled the plug and it's BONE DRY. No wonder nothing came out when I pulled the speedo.

[whtbaron]

So are you suspecting a leak, or did somebody forget to fill it up the last time it was out?

[forhire]

The brake drum unit wasn't oil soaked. That is why I was so puzzled. It runs smooth. I can't imagine it would have survived long without oil. It's possible it was greased. I wasn't planning on rebuilding it but now I think I'll have to crack it open and take a look. I suspect the transmission likely was run low on oil at some point. I didn't have a puller small enough to pull the bearing and look at the 5th gear journal. I'm hoping the output shaft isn't damaged.

[farmersammm]

https://www.oilburners.net/threads/z...ilshaft.69199/

[farmersammm]

Neither of my F-350's have this feature (THANKFULLY).

I searched, although a very limited search, for a way to delete the thing, but can't find anything about a possible solution.

[John T]

I was thinking possibly it had been filled with gear oil and that's why it ran hot but it just had burned ATF. I replaced it with Mercon V which I believe is semi-synthetic but I didn't drive on it aside from pulling it into the shop. It didn't sound very nice after changing the oil. Something is making noise.

I take it this truck is a 2WD ?

If not, how is the transfer case?

I'm pulling my hair out right now trying to figure out what I should use for transfer case fluid.

Some guys say use Mercon V

But I've heard Ford recommends
XL-12 Ford transfer case fluid
Which is now discontinued.

I "heard" mercon LV is the new suggested replacement but when you read the bottle it says do not use in transfer cases.

Highly confusing.

[whtbaron]

I take it this truck is a 2WD ?

If not, how is the transfer case?

I'm pulling my hair out right now trying to figure out what I should use for transfer case fluid.

Some guys say use Mercon V

But I've heard Ford recommends
XL-12 Ford transfer case fluid
Which is now discontinued.

I "heard" mercon LV is the new suggested replacement but when you read the bottle it says do not use in transfer cases.

Highly confusing.

You may have read this one already....https://torqueking.com/ford-full-siz...r-case-fluids/

[forhire]

I take it this truck is a 2WD?

You are correct. No transfer case... if there were it would have been bone dry.

There is definitely a lot of crazy ideas out there when it comes to lubrication. I'd imagine if it originally had Mercon than the modern Mercon V would work fine.

The rebuild kit arrived today so I decide to tear it down. Knowing what I know now I should have done a complete tear down day one. The transmission was definitely ran low on oil at some point. I'm amazed it ran nearly 50 miles before smoking. All the roller bearings are wasted. Main shaft is scrap. Lots of galling. The bores on most of the gears are trashed. It was a booger to disassemble. It looks like I'll need a full gear set.

5th gear was bad as I expected but it just kept getting worse and worse.

[12V71]

Ouch. This kind of surprise is why I stopped trying to rebuild big truck transmissions and just order up a reman unit. Usually I have the replacement the next morning.

[farmersammm]

You are correct. No transfer case... if there were it would have been bone dry.

There is definitely a lot of crazy ideas out there when it comes to lubrication. I'd imagine if it originally had Mercon than the modern Mercon V would work fine.

The rebuild kit arrived today so I decide to tear it down. Knowing what I know now I should have done a complete tear down day one. The transmission was definitely ran low on oil at some point. I'm amazed it ran nearly 50 miles before smoking. All the roller bearings are wasted. Main shaft is scrap. Lots of galling. The bores on most of the gears are trashed. It was a booger to disassemble. It looks like I'll need a full gear set.

5th gear was bad as I expected but it just kept getting worse and worse.

Before you pile a ton of money into it, look for a parts truck. Or look for a reman that doesn't have that ridiculous parking brake.

This sucks.

[52 Ford]

You are correct. No transfer case... if there were it would have been bone dry.

There is definitely a lot of crazy ideas out there when it comes to lubrication. I'd imagine if it originally had Mercon than the modern Mercon V would work fine.

The rebuild kit arrived today so I decide to tear it down. Knowing what I know now I should have done a complete tear down day one. The transmission was definitely ran low on oil at some point. I'm amazed it ran nearly 50 miles before smoking. All the roller bearings are wasted. Main shaft is scrap. Lots of galling. The bores on most of the gears are trashed. It was a booger to disassemble. It looks like I'll need a full gear set.

5th gear was bad as I expected but it just kept getting worse and worse.

Just because Mercon V is NEWER than Mercon, that doesn't make it better for your application. They had good enough chemistry/technology back in the 70's, 80's, 90's (when did Mercon come out?). Mercon, as I understand it, has a different additive package than Mercon V.

The additive package is the key.

Sent from my Lincoln Buzzbox using Tapatalk

[farmersammm]

https://www.aftermarketnews.com/ford...or-mercon-atf/

[forhire]

Before you pile a ton of money into it, look for a parts truck. Or look for a reman that doesn't have that ridiculous parking brake.

This sucks.

I'm looking. The 2WD transmission is kinda hard to find especially with the parking brake.

Ouch. This kind of surprise is why I stopped trying to rebuild big truck transmissions and just order up a reman unit. Usually I have the replacement the next morning.

I would have bought the reman if it wasn't a month out. I figured I could sort this one faster. Now I'm not sure. I'll need to clean everything in the morning and see what my parts bill will be. I was thinking I'd see something similar to the reverse idler, minimal wear, new bearings and I'd be back in business.

[farmersammm]

Sort of off topic................ There's also a lot of controversy surrounding gear oil containing EP additives, and the bad effect these additives have on yellow metals.

Yeah...........it's not a great product for older transmissions that have bronze synchros and such...........but the time it takes to actually ruin these parts is substantial....very substantial, compared to running those gearboxes without oil

I think you can still find non EP gear oil, but it's fairly hard. I run a modern EP oil in my tractors, and have had absolutely no problems with damage to the bronze parts. Or if there is damage, it's microscopic, and will probably not cause a problem in my lifetime.

[farmersammm]

I'm looking. The 2WD transmission is kinda hard to find especially with the parking brake.



I would have bought the reman if it wasn't a month out. I figured I could sort this one faster. Now I'm not sure. I'll need to clean everything in the morning and see what my parts bill will be. I was thinking I'd see something similar to the reverse idler, minimal wear, new bearings and I'd be back in business.

If bellhousings match, and frame mounts match, try to ditch that stupid parking brake, and go with the non parking brake tranny. It's a source of problems according to everything I've read. You'll only be out the cost of a modified driveshaft I'd imagine.

[John T]

Just because Mercon V is NEWER than Mercon, that doesn't make it better for your application. They had good enough chemistry/technology back in the 70's, 80's, 90's (when did Mercon come out?). Mercon, as I understand it, has a different additive package than Mercon V.

The additive package is the key.

Sent from my Lincoln Buzzbox using Tapatalk

A friend who owns a garage said they use Synthetic ATF in ford transfer cases ... didnt ask about manual trans , but probably the same.

Im prolly gonna use this in my transfer case...

[John T]

New shift boot and call it good?

That's not a shift boot...

It's an oil fill hole cover.

[forhire]

B&R has one in Nevada, it will be here in a week. I'm going to throw it in and see how it goes. I sent over my shopping list to Zumbrota for a parts quote. If the parts are reasonable I'll rebuild this one as a spare. It would have been a LOT cheaper to simply wait the month for Zumbrota to build a reman. Lesson learned. I was trying to save time and money. Of course I've learned a lot. At least I'm not taking out loans for my higher education.

[whtbaron]

If bellhousings match, and frame mounts match, try to ditch that stupid parking brake, and go with the non parking brake tranny. It's a source of problems according to everything I've read. You'll only be out the cost of a modified driveshaft I'd imagine.

But how do you pass safety with no parking brake? Then you need the matching diff with cables...

[farmersammm]

But how do you pass safety with no parking brake? Then you need the matching diff with cables...

I'd imagine if you looked under the truck, the backer plates on the brakes already have the setup for cable brakes...........if not, it's just a swap for different backer plates and actuators, and getting a junk parking brake system to install on the frame, and in cab. I imagine the 90 model had drum rear brakes.

Safety inspection?????????????? What is a safety inspection???????? We no have safety inspections here. They're a thing of the past in this State. We just run around until our wheels fall off

My old 60's Dodge trucks had external band safety brake drums on the output shaft. Just a drum with brake bands. Simple, and actually functioned as a SAFETY BRAKE that could stop the vehicle at moderate speeds.

[John T]

Just leave it in gear and throw a wood block under the tar ...

[forhire]

The auto wrecker called me this morning and said the case was cracked. Looks like they pulled the tranny without removing the starter but that's only a guess. They wanted to know if I still wanted it... no discount. Even at core price it would have been a gamble.

Spoke with Zumbrota again this morning and it's very clearly a 4x4 version based upon the main shaft numbers and the tail housing numbers. None of the numbers matched up on the internals except one synchronizer assembly. They are recommending I buy the reman and they may have the correct 2WD unit in stock. Fingers crossed.

[forhire]

Just got off the phone with Zumbrota and they have confirmed that indeed my Super Duty came with this 4x4 transmission and it uses the transmission brake assembly because it is fitted with a Dana 80 rear end and there wasn't enough room for hub mounted parking brake assembly on the rear. Good news is they have identified all the internals required to put it back together. Now I just need to decide if I buy the parts and put it together or simply wait for a reman with an 18 month warranty. In any event if I'd ordered the transmission we thought it was a couple weeks ago I would have likely received the wrong transmission and really been delayed.