# Borg Warner Egeardrive 31-03 8.28/1



## boekel (Nov 10, 2010)

*Borg Warner Egeardrive 31-03 8.28/1 - pictures of internals - how to lock the diff*

I have two sets of siemens motor + DMOC645 + Borg Warner Egeardrive 31-03 8.28/1 gearboxes.
As I want to use those sets in my boat, I have to lock the differentials so I can get all power into one axle (to the prop-shaft)

I made some pictures of the inside of the gearbox, for all pictures see:
http://boekel.nu/foto/14/2014-08_borg_warner_egeardrive_31-03/



















The parking brake, I think I can live without it 









the insides...









Parking brake in action.









Size comparison (30cl bottle)









The differential.









close up, gears aren't machined.









How to lock up this thing?


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## samwichse (Jan 28, 2012)

A couple welds in those crown gears would do you.


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## RIPPERTON (Jan 26, 2010)

Thanks for showing these picks Boekel.
I still cant believe this is just a single speed transmission. And those cast bevel gears !!!
For the weight size and half the cost you could get a Daihatsu 3 speed automatic.


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## boekel (Nov 10, 2010)

samwichse said:


> A couple welds in those crown gears would do you.


I don't really like the idea...unless I'm convinced it won't produce long term problems (welding material that's not made te be welded...). Any breakouts could destroy the whole gearbox 


I'm open for alternatives, a straight though (rwd) gearbox would be perfect.

But as I already own these packages and they fit together so nice...

Even more ideal would be a way to fit both motors to one axle with at leas 7x reduction, for now I'm planning on just putting two sets behind each other, one driving the second one, the second one driving the propshaft.
(two propshafts would be ideal...but that's a lot of extra work as my boat only has one prop at the moment)


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## Roy Von Rogers (Mar 21, 2009)

If this is an open rear end, if you lock one side, only the other side will turn.


Roy


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## aeroscott (Jan 5, 2008)

What a beautiful vessel , very efficient . How long and tonnage ? 
What size prop and shaft .
There is some old gear boxes used on GM 671's , where 2 or more engines have 1 output.


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## kennybobby (Aug 10, 2012)

+1 on what Roy said. You could get a splined stub shaft and weld/bolt it to a flange plate, then use the tapped holes in the housing to lock the flange in place.

That must be some special metal for casting the spider gears in that diff--or they forgot to grind the teeth...


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## boekel (Nov 10, 2010)

Roy Von Rogers said:


> If this is an open rear end, if you lock one side, only the other side will turn.
> 
> 
> Roy


Yes but how to lock one side...also the force on the gears will double (but they won't turn so shouldn't be a problem?)



aeroscott said:


> What a beautiful vessel , very efficient . How long and tonnage ?
> What size prop and shaft .
> There is some old gear boxes used on GM 671's , where 2 or more engines have 1 output.


26,4 meters, about 70 tonnes atm. shaft...think it's 65mm, prop 32x??(18?)
Thanks!



kennybobby said:


> +1 on what Roy said. You could get a splined stub shaft and weld/bolt it to a flange plate, then use the tapped holes in the housing to lock the flange in place.


I don't understand, lock it to the outside? then I only have half the reduction and the spidergears will be worn in no time.


> That must be some special metal for casting the spider gears in that diff--or they forgot to grind the teeth...


cast or sintered I think, I'd rather not weld on it to be sure.


I think I'll draw a completely new hub to replace the diff, see what the cost will be, than I can also use a thicker axle...to be continued!


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## RIPPERTON (Jan 26, 2010)

Just get rid of the small bevels and get a longer piece of axle spline that goes across both big bevels. That will lock it without welding.


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## boekel (Nov 10, 2010)

RIPPERTON said:


> Just get rid of the small bevels and get a longer piece of axle spline that goes across both big bevels. That will lock it without welding.


Nope, the small gears hold the bigger ones, the axle through them gets all the force / moment.


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## Karter2 (Nov 17, 2011)

RIPPERTON said:


> Just get rid of the small bevels and get a longer piece of axle spline that goes across both big bevels. That will lock it without welding.


...but once you remove those small bevels, there won't be any drive connection between the diff casing and the axle shaft... Ie:- no drive !


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## aeroscott (Jan 5, 2008)

I love the shear line (top of ladder touches) and rounded bilges (vertical meets bottom). How much draft? Whats the history?
I think thats to small a gear box. Maybe for a bow thruster it would be ok.


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## boekel (Nov 10, 2010)

aeroscott said:


> I love the shear line (top of ladder touches) and rounded bilges (vertical meets bottom). How much draft? Whats the history?
> I think thats to small a gear box. Maybe for a bow thruster it would be ok.


I'll make a seperate topic someday  in Dutch you can read (or watch the pictures) here:
http://www.machinekamer.nl/forum3/viewtopic.php?f=7&t=74

I agree the gearbox is not too big, but I just measured I can use a solid 40mm axle as an output axle, that would give some more strength, and this gearbox is quite 'beefier' than something like a PRM gearbox for a 80hp diesel engine.

And a 8 to 1 gear ratio is hard to find!


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## aeroscott (Jan 5, 2008)

I was at the scrap yard and saw a Renk Doromet 874 bus transmission . Massive 4 speed transmission , automatic. I wounder if it would have the right ratio.


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## TooQik (May 4, 2013)

What about something like this....

http://www.vernco.com/RearAxle4/


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## aeroscott (Jan 5, 2008)

How thick is the old hatch wood? Looks like 100mm.


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## aeroscott (Jan 5, 2008)

TooQik said:


> What about something like this....
> 
> http://www.vernco.com/RearAxle4/


 that should work.


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## Roy Von Rogers (Mar 21, 2009)

boekel said:


> I'll make a seperate topic someday  in Dutch you can read (or watch the pictures) here:
> http://www.machinekamer.nl/forum3/viewtopic.php?f=7&t=74
> 
> I agree the gearbox is not too big, but I just measured I can use a solid 40mm axle as an output axle, that would give some more strength, and this gearbox is quite 'beefier' than something like a PRM gearbox for a 80hp diesel engine.
> ...



I'm not an expert on marine conversions, but it seems that an 8:1 gear ratio is not right. In order to mimic the combustion engine, one would think it should be a 2:1 ratio, to reduce the high rpms to what a diesel or gasoline engine would produce, which would also simplify the selection of propeller to use.

I'm of course talking about using an ac motor.

At 8:1 the prop would have to have a large diameter and pitch.

Contact this company, they have the experience and know how to give you some advice....

http://newelectric.nl/



Roy


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## boekel (Nov 10, 2010)

Roy Von Rogers said:


> I'm not an expert on marine conversions, but it seems that an 8:1 gear ratio is not right. In order to mimic the combustion engine, one would think it should be a 2:1 ratio, to reduce the high rpms to what a diesel or gasoline engine would produce, which would also simplify the selection of propeller to use.
> 
> I'm of course talking about using an ac motor.
> 
> ...


This is the original engine:
https://www.youtube.com/watch?v=EgD4MrqUoLQ

The current (also AC) motor does max. 650 RPM (+- 60 kW), it's to fast for the propellor (it's a 6 pole motor, should do 1000 RPM), I want to increase the pitch to get the max speed under 500 RPM (at +/- 100 kW).

The siemens 5135-4WS14-Z motor is happy up to 4000 RPM, with the 8,3/1 reduction that gives 480 rpm which is perfect for my application.

I like the lock-conversions some people posted, problem is this gearbox the drive axles fit directly into the gearbox (no 'long axles' in a fixed axle) so not easy to lengthen the splines.

I'll measure the diff after the weekend and get some quotes to fabricate things.
Hopefully I can use the existing diff-casing as a base, using a long axle going through, locked to the diff-casing.


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## Duncan (Dec 8, 2008)

Hi
I think you are over-thinking
Simply take the drive-shaft you are not using and cut it to use it in reverse so that it goes across to join up with the shaft you are using,

You can simply use a pinned coupling to hold the two together,

Its a prop shaft so it should not see large impulsive loads unless you hit something, then replacing a pin could be a good way to save the rest of the system


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## dgr8n8 (Jul 25, 2014)

How about mini spool? it replaces the spiders. we use them in rock crawlers for a low cost fix with the option of going back to open. You would have to find out the spline count and match it to an axle of similar geometry. there are plenty of data sheets out there for that. Lock right, Auburn and JEGs all have mini spools and they usually run less than $100 USD.


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## Karter2 (Nov 17, 2011)

Duncan said:


> Hi
> I think you are over-thinking
> Simply take the drive-shaft you are not using and cut it to use it in reverse so that it goes across to join up with the shaft you are using,
> 
> m


But what about the planetaries and their shaft that happens to be in the way ?


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## Karter2 (Nov 17, 2011)

dgr8n8 said:


> How about mini spool? it replaces the spiders. we use them in rock crawlers for a low cost fix with the option of going back to open. You would have to find out the spline count and match it to an axle of similar geometry. there are plenty of data sheets out there for that. Lock right, Auburn and JEGs all have mini spools and they usually run less than $100 USD.


Don't you also have to match the spider shaft fittings also ?
Do you have a link to those data sheets for matching fittings ?


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## kennybobby (Aug 10, 2012)

Those are some great photos of the gearbox and clearly show the reason why Tesla is having drivetrain issues--it should be obvious to the careful observer, if you care to post your probable causes...


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## Karter2 (Nov 17, 2011)

.?? Are you suggesting there is some connection between this Borg Warner box, and the Tesla box .?


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## RIPPERTON (Jan 26, 2010)

aeroscott said:


> that should work.


*@^#$ that's elaborate but its where I was heading to with the single long spline through both side gears.
I was flicking down through all those pics and was wondering what they were going to do with the floating spider gears...


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## RIPPERTON (Jan 26, 2010)

kennybobby said:


> Those are some great photos of the gearbox and clearly show the reason why Tesla is having drivetrain issues--it should be obvious to the careful observer, if you care to post your probable causes...


No Oil ???


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## RIPPERTON (Jan 26, 2010)

kennybobby said:


> Those are some great photos of the gearbox and clearly show the reason why Tesla is having drivetrain issues--it should be obvious to the careful observer, if you care to post your probable causes...


But seriously... there should be washers between shafts and bearings.
Maybe diff carrier has too much end float.


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## kennybobby (Aug 10, 2012)

Those helical cut gears impart an axial load component to the gear shaft that must be reacted thru the bearings--but those 8-ball deep-groove radial bearings are not designed or able to carry much axial load. 'Forward' motion causes an axial load on the shaft in one direction, and 'Reverse' changes the axial load in the other direction, so both end bearings will 'get loose' over time and whine...

Angular contact ball bearings or thrust roller bearings will be required to solve the drivetrain issue.

oops i guess this is the slightly off the boat topic, but you had the great pictures of the gear guts here...

Great looking ski boat you'll have there!


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## major (Apr 4, 2008)

I've been through the factory where they made these. Those guys know how to make gearboxes. They've done it with the best of 'em for many years. There's nothing wrong with this


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## dgr8n8 (Jul 25, 2014)

Here is Auburn's version of the mini spools I was thinking might work. They and others have different axles that they fit. Just contact those manufacturers. Perhaps something as simple as a Spline coupler would work. You would have to cross drill it for the spider pin but it is a very low cost solution.


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## boekel (Nov 10, 2010)

dgr8n8 said:


> Here is Auburn's version of the mini spools I was thinking might work. They and others have different axles that they fit. Just contact those manufacturers. Perhaps something as simple as a Spline coupler would work. You would have to cross drill it for the spider pin but it is a very low cost solution.


Looks like the perfect thing!
Thanks for sharing.

In my case I decided to make a new hub for the gear, so I can use a 40mm (high strength) axle better suited for my application, that will be easier than adjusting the hub with the differential.

I will post updates if I get further


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## boekel (Nov 10, 2010)

Teaser!!!
























































Still waiting for the axle, will shrink-fit the gear on tomorrow


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## TooQik (May 4, 2013)

Looks good. 

Quick question though, how is this new differential held in place in the gearbox housing, as there does not appear to be any provision on the new unit to fit into the existing bearings?


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## boekel (Nov 10, 2010)

TooQik said:


> Looks good.
> 
> Quick question though, how is this new differential held in place in the gearbox housing, as there does not appear to be any provision on the new unit to fit into the existing bearings?


The new axle will do that, therefore I installed bigger seals so the axle fits through there.


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## boekel (Nov 10, 2010)

Done 
40mm 42CrMoS4+QT+SH high strength axle in place.


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## bjcouche (May 17, 2013)

I know this thread is old, but it's the most info on the 31-03 I've found anywhere... In my EV conversion I cant find the proprietary splined CV ends to fit the Borg Warner. In your work with the diff carrier, did you ever find out if the diff carrier is a standard part? I'm hoping I can buy a "replacement" carrier with a common sized splined shaft. Then just replace the carrier and install off the shelf CV ends.

Brian


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## boekel (Nov 10, 2010)

I don't know, hopefully someone else?


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## bjcouche (May 17, 2013)

Boekel, You replaced the oil seals... Do you know the dimensions or part numbers that the original one was and the one that you used? Did you use 40mm ID oil seals? I'm thinking that if I can replace the oil seals with 40mm ID seals, that there might be different axle options available.


I'm getting some more info on this as I do more research. It turns out that an inner CV joint from a Volvo XC90 will fit the Borg Warner. However, it will not work when using a siemens motor because the motor interferes with the CV joint, thus you have to have an intermediate shaft. Another problem is that the XC90 half shaft is designed to plunge (axle go in and out) on both the inner and outer joint. Thus the inner joint only has HALF the required plunge distance. This means that the joint on the vehicle you are converting also must have this type of joint on the outer CV... Long story short, I may have found a different axle that might be a better fit, but the oil seals are the wrong size... I'll know more when the parts arrive and I'll update this site and start my own thread with the info to help others.

Brian


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## bjcouche (May 17, 2013)

The original oil seals are 35IDx55OD. I was able to replace them with 40IDx55OD seals. Once the gearbox has 40mm oil seals, Volvo 850 shafts will fit perfectly into the gearbox.


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## boekel (Nov 10, 2010)

That's valuable information! Tanks!


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## akashi75 (6 mo ago)

does anyone have a borgwarner 31-03 for sale?


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## remy_martian (Feb 4, 2019)

What's the most you'll pay for one is the better way to ask, imo.


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## akashi75 (6 mo ago)

I'm willing to pay the right price if the condition is good.


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## remy_martian (Feb 4, 2019)

Yeah - that'll pull the ones sitting there off the shelves. This is a seller's market for this item.

Some of us have them, but "right price" is not going to bring them forward.


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