1999 Suzuki DT140 Lower Unit What did I do wrong?

james roach

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Here is the background. I have twin DT 140's on my boat. Last fall I decided to replace the water pumps because I had a suspicion that they had never been changed. After removing the water pumps from both motors I decided to replace the corroded Drive Shaft housings as well. I purchased the assemblies for both motors. I installed all of the new parts and put the motors back together. I ran each motor for about 20 minutes on the hose with ear muffs and then took them to the water. As I began to throttle up to plane the boat off about half way up on plane the port motor makes a runaway sound as if the prop had slipped then the motor locked up. I eased back on the other engine and when I got the boat home I discovered the port LU was locked up. I tore it down to the Drive Shaft housing and that bearing had locked up. The needles were everywhere. I drained the oil from the lower unit and it had metal shavings in it but no chunks.

Repair, replace LU where do I begin? What did I do wrong? Thanks in advance for your replies.
 

99yam40

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

Sounds like it was not getting any lube, but have no idea why. The only one I have seen do that was a DT150 that the owner forgot to fill the lower unit back up after he drained it. Said he was going to after the bought some next time in town, but a senior moment got the best of him.
But it ran for hours out into the Gulf of Mexico before to locked up, good thing he had two on that boat.
There was a plastic grooved part on the shaft that is suppose to work oil up to that top bearing maybe your broke.
 

james roach

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

I did fill it up with oil but when I took the housing out and got to the roller bearing there was no sign of oil. I do not recall seeing a spacer,washer,shim or anything between the roller bearing and ds housing. Now the shaft has a ding in it where it locked up. I dont know whether to get another unit or work on this one.
 

99yam40

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

If it ended up like the 150 I saw the housing and the shaft was shot. all that metal came from some thing that came apart. You maybe able to find a used on or an after market one on line.
 

james roach

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

This has got me worried concerning the starboard motor. It gave no signs of trouble when the port motor went. The DS bushing is a simple change out part correct? I don't think there are any shimming or washers involved. These lower units are hard to find used. Anyone got any suggestions? I search EBAY daily.
 

lakensea

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

Please post some pictures, as I am not sure what you mean by "drive shaft housing". The drive shaft housing is the piece between the lower unit and the engine assembly, and there is no bearing in it. Do you mean the entire gear case itself, or the prop shaft housing? There are a number of shims and thrust washers, and gear backlash and prop shaft endplay must be checked when replacing any components. Did you pressure test and vacuum test the lower unit after assembly? Did you use a service manual? I suggest you bring the other lower unit to a qualified Suzuki dealer and have them dissasemble it and check it for you.
 

stylesabu

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

im not sure, but don't twin motors spin opposite of each other? Is it possible that you put 2 of the same parts on, 1 being wrong. ie 2 lefts or 2 rights?
 

lakensea

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

Part number 26.



http://http://store.brownspoint.com/dt140/fig020-1408601.asp

I did dot tear it further down than assem 26. I did not see anything that needed to go from the old assem to the new one.

OK, I see, it's the drive shaft bearing housing. On the old 2-stroke engines they show it on the water pump parts page. There is a shim, thrust washer & thrust bearing under the housing - make sure that they were there, however IF the only damage is the drive shaft bearing, then the usual cause of that is low gear oil level. The only way to check that would be to tear down the rest of the lower unit. You would have to do that to repair it anyways as all your bearings will need to be replaced, and gears checked over carefully. I assume you filled the gear oil from the bottom up.
 

lakensea

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

im not sure, but don't twin motors spin opposite of each other? Is it possible that you put 2 of the same parts on, 1 being wrong. ie 2 lefts or 2 rights?

Suzuki did not have counter-rotating DT140 lower units.
 

james roach

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

If there were any parts that needed to come out of the old assem and go into the new one then I am in trouble.
 

James R

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

When you replaced the bearing housing did you pay attention to the shimming. Shims are fitted to ensure the correct end play of the drive shaft. If the shimming was incorrect that may have caused the bearing failure. Failure of the bearing would result in seal failure and the oil would have been pumped out of the case.
Go to brownspoint .com to see the assembly. I don't have the specs for correct shimming but I will go into the manual I have to see what is there.
 

james roach

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

I believe the shim and the thrust washer are located under the roller bearing. It did not fail only the needle bearing inside the housing assembly(part 29).
http://store.brownspoint.com/dt140/fig046-1408601.asp


It appears as though I am missing parts 7 and 8 from this diagram. There is a groove in the bottom of the drive shaft housing and I bet the old ones were thrown away with the old housings.
 

lakensea

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

I believe the shim and the thrust washer are located under the roller bearing. It did not fail only the needle bearing inside the housing assembly(part 29).
http://store.brownspoint.com/dt140/fig046-1408601.asp


It appears as though I am missing parts 7 and 8 from this diagram. There is a groove in the bottom of the drive shaft housing and I bet the old ones were thrown away with the old housings.

This is what happens when you do not use a service manual. Now there is a good chance you have damaged the gear set from the drive shaft having way too much play. You also cannot just purchase the missing items and install them because the entire drive shaft/housing/pinion gear has to be set up in a special shimming fixture.

So now you either need another lower unit, or the help of a QUALIFIED Suzuki dealer.
 

Marion Moore

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

I think it was a bad bearing but that's just my opinion. A dry bearing should have run much longer than that without lube. I have taken apart my DT115/140 lower units many times and not run into any problems but I DID NOT change any bearings, just seals. I do, however, oil the bearing before I reassemble just for the heck of it.

If it were me, I would buy the parts that I needed and put it back together again. You would have some time invested but the parts wouldn't be too much. If it fails again you are no worse off than you are now. I might open the other LU just to make sure its bearings are oiled.
 

99yam40

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

I believe the shim and the thrust washer are located under the roller bearing. It did not fail only the needle bearing inside the housing assembly(part 29).
http://store.brownspoint.com/dt140/fig046-1408601.asp


It appears as though I am missing parts 7 and 8 from this diagram. There is a groove in the bottom of the drive shaft housing and I bet the old ones were thrown away with the old housings.

looking at that part diagram, seems that bearing #9 rides on a surface on #7 and a surface on #1 ,
all 3 of these parts along with the housing that #8 rides against were totally wiped out on the DT150 I was talking about before.
If these parts#7 & 8 are missing what was the #9 bearing riding on?
Which bearing are you speaking about? As I do not see the housing or bearing #29
 

james roach

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

Assem. 26 is in the waterpump exploded view. This is the first time in 20 years that doing my own mechanic work has come back to haunt me so I will accept my losses for that. Thanks for the lecture Lakeandsea.

Concerning the port motor that locked up I have already started looking for a good used replacement gearcase. The starboard motor I am taking to my local dealer to have reshimmed. Sometimes you win and others you lose. Thanks for all the responses and I will post the dealer's findings.
 

james roach

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

The starboard lower unit is in the shop right now being reshimmed. I am still thinking about what to do with the port motor. Will post results. Thanks to all.
James
 

Outsider

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

I dont know whether to get another unit or work on this one.

What happened to it the last time you worked on it ... :redface:
 

james roach

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Re: 1999 Suzuki DT140 Lower Unit What did I do wrong?

I dont know whether to get another unit or work on this one.

What happened to it the last time you worked on it ... :redface:


Or have it rebuilt. Is that better?
 
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