SX-MHP first time U-Joint replacement

st0n3

Cadet
Joined
Jun 24, 2012
Messages
17
(moving this conversation to new topic to help others find in the future)

Engine: Volvo Penta 8.1 Gi-F (2004-2005)
Transom: SX-MHP
Drive: DP-SM 1.78 (M22)

This is my first time replacing a U-Joint, so any suggestions / corrections / tips would be VERY much appreciated. Below is the information that I have found so far and where the results of the project will be posted in order to help others.

It is very important that our boats function reliably and none of us want to dig into the pinion gear assembly to redo this project, so let's document how to "do it right the first time".

Researching various forums and YouTube videos led to the following info and questions.

Here are the installation instructions:
Volvo Penta Universal Joint Kit - Installation Instructions (3860842)

... and the exploded parts diagram:
DP-SM Outdrive - U-Joint and Bearing Carrier

The U-Joint Kit comes with the pinion gear retainer screw (#4 on parts diagram) and crush sleeve (#5).

The existing pinion carrier oil seal (#8) looks fine on my drive. No leakage. Just need to replace the U-Joint.

I will measure the running torque before disassembly to establish a base-line. The general wisdom appears to be to carefully clamp the pinion gear housing (#10) in a vice and use a precision torque gauge (I will be using a 0-30 in.lb. dial wrench) to turn the pinion gear retaining screw (#4) which is either a PTX-500 torx (old) or 11 mm 12-point socket (new). Note that the torque required to start the motion may be higher than to keep it going. We want the torque value to keep it going. The proper specs are between 9 - 14 in.lb.

Wondering if I can just replace the U-Joint by:
1. Remove the pinion gear retainer screw.
2. Pull out the U-Joint (one video suggested hammering using a wooden dowel. best method? is it tight?).
3. Put in the new U-Joint.
4. Replace the pinion gear retainer screw, tightening it very carefully to achieve the base-line running torque.


Q1) How important is it to press out the bearings from the pinion bearing carrier and install a new crush sleeve?


The instructions call for four Volvo special tools to remove and then reinstall the bearings after replacing the crush sleeve. Haven't been able to locate these specific tools in stock at one place yet and they are a bit pricey. There probably is a good way to do this work without the Volvo tools that are well known to a Volvo Jedi. Humble Padwan would love to learn the ways of the Jedi. :^)


Q2) If the crush sleeve should be replaced, then what is the best method to do so (i.e. correct tools to use to remove the bearings and how to best use them)?


Thanks in advance for any words of wisdom as I head out into uncharted waters.

- Brad
 

billbayliner

Chief Petty Officer
Joined
Jun 30, 2006
Messages
553
I had to sign in and answer this as your questions display your lack of knowledge with gear sets....... (Not trying to be an arse actually signing in to save you.)

If replacing the entire shaft / fork assembly, take the drive gear bearing assembly from the upper and BRING IT to an experienced mechanic. This is NOT something that a layman should touch as you will lose the upper if the rolling torque / pre-load is not done correctly.

And you need specialty tools for the job also....
 

st0n3

Cadet
Joined
Jun 24, 2012
Messages
17
Hey Bill,

Thanks for the response. It is really helpful when an experienced person recognizes a difficult procedure that could be outside the ability of someone. Thanks for caring enough to take the time to log in and post. It certainly is an option to take in the pinion carrier to our Volvo shop and have them do the U-Joint replacement (all the parts are already ordered and should be here tomorrow).

With that said, the instructions that come with the U-Joint kit (see link in post above) seem pretty straight forward. I have a dial torque wrench that should be able to measure the rolling torque so that the pre-load is set correctly. The only tools that I don't have are the ones to press out the bearings so that the new sleeve can be installed, nor the ones to press the bearings back in again. If those tools had been readily available to order, I would have bought them too, but it doesn't look like I can get them in time.

While not a professional mechanic, I do almost all my own car repairs, have restored a couple of vintage motorcycles, and have done most of the work on my boat for the past 12 years or so - including successfully replacing the cone clutch. I also have access to a couple of machine shops.

If a new sleeve is pretty much necessary when replacing the U-Joint, then I will take the pinion carrier to the Volvo folks who (hopefully) have the correct tools and can do it right. After reading a number of posts from people that have replaced the U-Joint in similar drives, it didn't seem that all of them replaced the sleeve and just set the rolling torque within specs.

If not replacing the sleeve is a really bad idea, then that is what I would like to know.

Words of wisdom (and even criticism) from all are very much welcome. :^)

- Brad
 

st0n3

Cadet
Joined
Jun 24, 2012
Messages
17
Thanks for the suggestion about replacing the U-Joint without removing the input shaft. Hadn't thought of that. Just read the thread.

Is it true that simply replacing the U-Joint also requires re-shimming? I thought that if the U-Joint was replaced (say by taking to the Volvo dealer to get the pre-tension set correctly) that the same shims could be used on the pinion carrier.

Here is a photo of the U-Joint. As mentioned earlier, the bellows likely leaked just before the boat was put away for the winter.

uc


uc


- Brad
 

dypcdiver

Lieutenant Junior Grade
Joined
Nov 1, 2005
Messages
1,016
OK so you decided to go ahead and remove the input bearing carrier etc. your choice.

Now just mark up all the components so that you can reassemble them the exact same way. VP are supposed to have balanced the shaft assembly is the reason.

Replace the 2 sets of "U" joints then all should be fine. make sure to pack the needle rollers with plenty of grease to STICK them in place whilst reassembling.

So long as you have not disturbed the drive pinion, all should go back as it was.
 

st0n3

Cadet
Joined
Jun 24, 2012
Messages
17
Thanks for the guidance. You folks really have been kind.

The manual says that the rolling torque should be between 9-14 in. lb. In the video below, the rolling torque is measured and it never gets above 5 in. lb. - more like 3-4 in. lb.

Caveats: The input bearing carrier is just sitting in the vice, there is no pressure on it. Also, the torque gauge is brand new with an independent certificate of accuracy, so pretty sure it is measuring correctly.

It seems like the carrier is out of spec - even if I just replace the 2 sets of U-Joints without disturbing the drive pinion.

Based on the great input received on this forum, it seems like the prudent course of action is to take the carrier to a Volvo dealer and having them replace the U-Joint and set the pre-load.

Thoughts?

 

muc

"Retired" Association of Marine Technicians...
Joined
Jul 7, 2004
Messages
2,064
Thoughts?
I have reused the crush sleeve a few times on drives that are “loose” like yours is. You just need to make sure that the rolling torque is higher than when you took it apart. I wouldn’t reuse the bolt though. Back in the days before crush sleeves, this assembly was shimmed to get the correct rolling torque and the Volvo teachers were adamant about saving the old bolt for shimming and then putting in the new bolt at the end.
With that much rust I would recommend replacing the complete assembly and the seal. I’m pretty sure when you disassemble it you will find the yoke is rusted and pitted. I feel that just replacing u-joints is a “hack” job done because the mechanic doesn’t have the skills and tools to do the repair right.
You are checking rolling torque correctly. 3-4 in. lb. is a little lower than I would expect. Have you been using VP gear lube? Remember that 9-14 in. lb. is for new bearings. Don’t be surprised to get it back from a good shop set between 7-10 for used bearings.
You don’t need to reshim if you didn’t ruin the plastic shims when you disassembled. I do like to do a quick backlash check during reassembly just to be sure. I usually have the shifter off anyway because that seal should be replaced while you’re “in there” on any drive over 7 years old. They are a fairly common source of leaks.
I don’t know about work around’s for the correct tools because I’ve always had access to them. But the one I would want for sure is the fixture that you set the bearing carrier in for pressing. It takes quite a bit of pressure to start a new crush sleeve to start crushing. I wouldn’t want to attempt that with just the bolt.
 

st0n3

Cadet
Joined
Jun 24, 2012
Messages
17
Follow-up:

We ended up taking the U-Joint connected to the pinion bearing carrier to our local, Volvo certified marine store. We had all the replacement parts (U-Joint kit, new seal). The mechanics were 3 weeks out for repairs, but said that since the unit was pulled and they didn't have to track down parts, that they could fit it in same day for 2 hours ($200). Deal!

The mechanic that did the work took the time to talk with us and it was clear that he had done many similar repairs. He knew what he was doing. The rolling torque was tested when we got the unit back and it was spot on.

Lessons learned:
1) Probably best to have the pros handle this type of repair.
2) The Volvo tools that are described in the instructions are required - especially the bearing cup.
3) You need a good press. The sleeve needs to start compression using the press - not just the bolt.
4) You need to accurately measure the rolling torque, so make sure you have a sensitive (0-30 in.lb.) dial torque gauge.
5) Be very careful not to damage the shims when removing the carrier - they can (should) be reused.

... and 6) This forum has some really helpful folks that are willing to share their knowledge!

The boat is all put back together with a new U-Joint, new gimbal bearing, and new bellows. Everything looks great in our driveway test. We are taking it out on the lake this afternoon.

Once again, a big thanks to all that contributed to the conversation.

- Brad
 
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