Blown reverser seals???

[dustin502]

This morning I went out to tinker with my 350B. I started the engine and let it run for about 15 to 20 min, both the trans and reverser was in neutral. I was about to shut it down when I noticed oil pouring out from between the reverser and the engine. The oil was clean so it had to be coming from the reveser pump area. I pulled the engine out and at least a gallon of oil came out when I pulled the engine loose. I looked at the reverser pump and couldnt see anything obvious. I just went thru the reverser and replaced both gaskets and the front seal about a month ago. Is it possable the the reverser is building to much pressure? I hope someone can help me out, I have no idea! Any thought's or suggestions would be appreciated. Thanks

[jdemaris]

I just went thru the reverser and replaced both gaskets and the front seal about a month ago. Is it possable the the reverser is building to much pressure? I hope someone can help me out, I have no idea! Any thought's or suggestions would be appreciated. Thanks

If you're concerned about excess pressure, stick a gauge in and find out - but I doubt that's your problem.

That front seal leaks when . . . either the shafts are loose and not adjusted properly (too much end-play) - or - the front pump gears and/or pump housing are scored on the front face. That pump runs a max of 150 PSI and the pressure-sealing is done by flat metal against metal. Like any hydraulic pump, if the metal gets scored, pressure oil can get past it. If you pull it part, it will be easy to see. If the entire seal actually pushed out towards the front, it's a scored pump/exess pressure problem. If the seal is just torn up, you've got loose shafts.

What exactly did you do to the reverser when apart and how did you adjust the endplay in the shafts?

[dustin502]

jdemaris, I replaced the clutch shaft, all of the clutches (metal and fiber), all seals, o-rings and bearings. I also took apart the control valve, cleaned everything and replaced the o-rings and gaskets. I put all the shims back where they came out. I checked and adjusted the shaft end play using a magnetic base indicator. I felt confident that the end play was right. I just took the pump cover off. I dont see anything wrong with the seal and it was not pushed out. The only scoring I could see is in the housing(front cover and pump cover) The pump gears look good, there is some light swirl marks but everything feels smooth. So you think it's probally the scored pump cover? Do you know if they are still available form deere?

[jdemaris]

I dont see anything wrong with the seal and it was not pushed out. The only scoring I could see is in the housing(front cover and pump cover)

So you think it's probally the scored pump cover? Do you know if they are still available form deere?

No, if the seal isn't pushed out, I can't see how the pump caused any leaks. In fact, if the seal sealing-lip still looks good, the the spring is still in there - are you sure that leak isn't coming from somewhere else? It's not an area prone to leakage other than that seal. Are you sure the front cover gasket is intact, as well as the big o-ring packing that seals the pump housing to the front cover?

In most cases, when that front shaft leaks it's due to a failed centerbearing -inbetween the input shaft and the output shaft. It is the weakest part of the reverser and the first part to go bad if shaft bearing preload is too tight. I've seen many fail right after starting on newly rebuilt reversers. But, I can't tell from here. You've had it part and only you know if all is OK inside or not.

[dustin502]

The seal looks good and the spring is still there. The seal I took out was resessed down in the pump cover so I put the new one in the same way. Is this right or should it be flush with the cover? The o-ring looked good behind the pump cover. I havent pulled the front cover off yet to check that, I'll do that today. I'll need to recheck the end play after the front cover comes off right?

[jdemaris]

The seal looks good and the spring is still there. The seal I took out was resessed down in the pump cover so I put the new one in the same way. Is this right or should it be flush with the cover? The o-ring looked good behind the pump cover. I havent pulled the front cover off yet to check that, I'll do that today. I'll need to recheck the end play after the front cover comes off right?

We alway installed the seal flush, not recessed.

You can check the shaft end-play with the pump cover on, or off - it's makes no difference.

I'm not trying to make a big deal out of the adjustment - but I know it has been a major problem for many, otherwise good mechanics. I saw many newly rebuilt reversers burn up before they even left the shop.

Seems the main problem is this. Most people who have adjusted other bearings on shafts are used to being able to do it by "feel", like you would with something like wheel bearings. For that, it can work fine. Problem is - since the reverser has two shafts mounted on three bearing assemblies, it cannot be done by feel. Even if you've got it so tight there is NO endplay, and you have a bearing crush/preload instead, the front shaft will still wobble side to side when you put your hand on it and feel like there IS endplay. That is misleading. There is NO way to successfully check it except with a dial indicator, and even then it's not easy. If out, the best way to do it is - stand the reverser upside down with the bottom edges of the case on blocks. Rear shaft pointing up in the air with dial indicator mounted. Then, from the bottom pry up on the input shaft and measure. Must have at least .002" endplay and no more then .004". Note that just about any bearing preload or crush will quickly burn up the center-bearing - especially in older 350s that use a much smaller center-bearing than later ones.

If you aren't pulling the reverser out - getting a good measurement is not easy since gravity is pushing down on parts. But, mount a dial indicator on the input shaft and - force hard - the shaft to the front and then to the back. A pry bar and Vise-Grips can help.

Have you checked the oil port where it travels from the front cover to the reverser case through the gasket? Any chance it's leaking there?

[dustin502]

When I adjusted the end play on the shafts, I stood the reverser up on the bellhousing with the output shaft facing up. Set the dial indicator up on the output shaft and went thru the filter hole with a prybar. After shimming I ended up with .002"-.003" on both shafts. I felt good about it then but, I'm second guessing myself now. I'll drain the reservoir into a clean white bucket to see If I can find any evidence of bearing failure. I pulled the front cover off the reverser and the gasket looked good. Do you think it might be leaking by the seal because it was in to far? Also, in the bottom of the bellhousing there is drain hole with a cotter pin in it. Is that suppost to be there?

[jdemaris]

When I adjusted the end play on the shafts, I stood the reverser up on the bellhousing with the output shaft facing up. Set the dial indicator up on the output shaft and went thru the filter hole with a prybar. After shimming I ended up with .002"-.003" on both shafts. I felt good about it then but, I'm second guessing myself now. I'll drain the reservoir into a clean white bucket to see If I can find any evidence of bearing failure. I pulled the front cover off the reverser and the gasket looked good. Do you think it might be leaking by the seal because it was in to far? Also, in the bottom of the bellhousing there is drain hole with a cotter pin in it. Is that suppost to be there?

Sounds like you did it all correctly. I assume the pilot bearing in the flywheel is still in good shape. If the center bearing in the reverser had failed, you'd know it. They just don't go a little - it's usually catastrophic.
In regard to the seal being pushed to far in - it shouldn't cause a leak as long as the seal lips are still riding on a good surface on the input shaft.
At this point - without seeing it myself - it has me stumped. The only places it CAN leak are - from the shaft-seal area, or the sealing area between the pump housing and front cover (sealed with a big o-ring), or the front cover sealling area (sealed with a gasket).

In regard to the little hole with the cotter pin, it's just a weep hole to let any small leaks, residual fluid, moisure, etc. to drain out the bottom. Cottem pin keeps it from getting plugged with dirt.

[dustin502]

I drained the fluid out and it was clean, I took the filter out and there were no shrapnel in the bottom either. I think i'll replace the gasket, O-ring and the seal and try it again. Honestly, there was so much fluid in there that you couldnt tell where it was coming from. I've just put the engine back in last week and I've let it run for about an hour. it probally took that long to fill up the bellhousing. I replaced the pilot bearing when I upgraded to the new isolator. I'll get the parts coming and get it back together, I'll let you know what happens. thank you for your help and advice.

[dustin502]

I finally have a few days off from work so I was able to work on the reverser again. I installed a new gasket o-ring and seal for the pump. I couldnt get an accurate reading of the end play so I pulled the reverser back out and set it on the ground. The end play checked at .003". Hopefully over the next few days I'll get everything back together and try it again.

[jdemaris]

I finally have a few days off from work so I was able to work on the reverser again. I installed a new gasket o-ring and seal for the pump. I couldnt get an accurate reading of the end play so I pulled the reverser back out and set it on the ground. The end play checked at .003". Hopefully over the next few days I'll get everything back together and try it again.

That makes my back hurt just thinking about pulling it twice. I'd be nervous with a leak like you mentioned and not finding a cause. You ought to be able to see it. Maybe you ought to rig it so you can test before installing again. We did at times in the shop. Loop the cooler lines together, fill it with oil, and spin the front shaft with a 1/2" electric drill or equiv.

[dustin502]

That sounds like a good idea, Hopefully I will not get a chance to try it any time soon. I got the reverser and the engine stuck back in, All the bolts are torqued on the reverser and i'm missing a bellhousing bolt. My shop probally ate it! I really need to stop working and start cleaning! Hopefully I'll get everything hooked back up and get it started tomorrow. I forgot to mention that the front cover was missing a dowel bushing, I didnt notice that until I was putting it back together. Anyway it has 2 now. Wish me luck!