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reb78

GKN Overdrive Strip Down

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Thats bad luck Ralph. If I had the choice though i would run the overdrive sump instead of the transfer box one. 

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Oh, also, the thread in the OD base for the sump is 1/4-28 UNF if you need to source different bolts. 

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That is an interesting development Ralph. And something I had not thought of. I've spent some of this weekend doing some design work on the sump i plan to make. Looks like I'm heading back to the drawing board.

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On 4/18/2019 at 4:21 PM, Ducko said:

My gkn overdrive was playing up badly with slipping gears mostly. I changed the atf oil and cleaned the filter and it worked like new for A few thousand miles. Its now leaking oil between the transfer box and the gkn, anyone got advice? Is it a big job to remove it and can i return the defender to being used without an overdrive. ?

The gasket may just have become too compressed and the unit just needs nipping up on the bolts.  Failing that, removing it to replace the gasket, either with a new gasket or RTV sealant, should sort it out.  A small, rectifiable oil leak is no reason to revert to standard gears, but it does need attention before your oil levels can drop enough to harm anything.

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How much overlap is there on the two sumps, Ralph?  Would it be possible to shave both of them a little on the outside without breaching the inner faces, or does a more substantial lump need removing?  If it's only small, you might be able to use those special alloy brazing rods like George used on his RR floor to use with small ali patches or even to internally reinforce shaved corners.

In the mean time, if you run only one of the big sumps, I echo Reb's view that the overdrive sump is more important than the 230's.  If you did fit the Roamerdrive, then the 230 sump would be of great benefit, but with the GKN, it's not going to make a world of difference.

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Needs a good lump removing from the overdrive sump,  just got to pack tools up & clean my grubby hands. 

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I'd leave the standard transfer box sump on. LT230 transfer boxes are stronger than overdrives.

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4 hours ago, reb78 said:

Oh, also, the thread in the OD base for the sump is 1/4-28 UNF if you need to source different bolts. 

Thanks for that info, will get more bolts & swap the sumps over, though I really would like both on. 

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Photos of correct corner with measurements, a fair lump approx 50 x 50 x 50mm would have to be removed & resealed to make it oil tight. 

IMG_20190505_183622.jpg

IMG_20190505_183614.jpg

IMG_20190505_183446.jpg

IMG_20190505_183428.jpg

IMG_20190505_183252.jpg

IMG_20190505_183223.jpg

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That's a big lump, but the oil capacity is probably quite small and so it won't make a great deal of difference.  Still, being so small and the GKN so oil sensitive, and the 230 so robust and having so much more oil, I'd look to trim the 230 sump.

How about making a spacer neck that would be sandwiched between sump and overdrive to drop the sump down?  It'd further increase oil capacity, too, and need only be a sheet (or two) of ali cut to size with the bolt hols drilled.  That would be the simplest, neatest and most reliable solution.

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A spacer would be a solution, There is a place where I could get one made, would need it puting on a CAD file though,which I know nothing about, 

I'll have to measure & see how deep a spacer would need to be to obtain a small amount of clearance between TB & OD sumps. 

also the oil filter extension tube that comes with the sump would need to be longer to ensure it pickes up from the bottom of oil contents.

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Ralph, I have been drawing all the bits up on CAD for the Overdrive over the last few days. Soon I should be able to supply a set of Gaskets for sensable money, a sump that fits. And I can certainly make you a spacer up to make yours fit.

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22 minutes ago, vulcan bomber said:

Ralph, I have been drawing all the bits up on CAD for the Overdrive over the last few days. Soon I should be able to supply a set of Gaskets for sensable money, a sump that fits. And I can certainly make you a spacer up to make yours fit.

Oh sounds good, on another thought if my existing sump was cut down by 50mm & the existing end was welded or bolted back in place, would that work? The total oil capacity would still be more than the overdrive existing oil capacity. 

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There are no support or baffles beyond the filter housing, just took these 2 photo's

Checked this sumps capacity with water it holds 1100ml or 1.1litres when filled level to the machined face. 

IMG_20190506_110430.jpg

IMG_20190506_110902.jpg

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On 12/17/2018 at 12:57 PM, reb78 said:

Be curious to know if it retains the small gauze filter and whether the oil pickup is extended into the sump or not when you get it Ralph. Also whether it still has a magnet glued in there as I find mine does catch some fine particles. The fella selling these wasnt that helpful when I contacted him previously - didnt seem to know when he might even expect stock!

Missed replying to this reb, the existing filter is reused, it sits in the machined area inside the big sump & has a extension tube & 2 'O' ring seals. 

IMG_20190506_111835.jpg

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1 hour ago, western said:

Oh sounds good, on another thought if my existing sump was cut down by 50mm & the existing end was welded or bolted back in place, would that work? The total oil capacity would still be more than the overdrive existing oil capacity. 

Me and Richard were discussing this yesterday, it is certainly an option to cut it and weld it. However, I don't know how well the Ali would weld with it being cast, hopefully someone in the know will see this and give you an answer. I doubt there is enough wall thickness there to bolt it back together.

My current plan is to make a sump that will extend to the front of the overdrive and also backwards under the crossmember to get the capacity. I'm just waiting to find out what standard material sizes I can get to make it from. I don't know if you'd be able to move the sump you have at the minute on and use one of mine, which is another option.

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Cutting and welding would work, but it's got to be easier and more reliable to fit a spacer, even if that means the GKN sump is in the way if you need to drop the 230 sump.  Given the expense of the GKN and its oil issues, and the expense you've gone to with the new sump, it'd be a shame to lose that little bit of capacity and run the risk of cracks and leaks.

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3 hours ago, vulcan bomber said:

Me and Richard were discussing this yesterday, it is certainly an option to cut it and weld it. However, I don't know how well the Ali would weld with it being cast, hopefully someone in the know will see this and give you an answer. I doubt there is enough wall thickness there to bolt it back together.

My current plan is to make a sump that will extend to the front of the overdrive and also backwards under the crossmember to get the capacity. I'm just waiting to find out what standard material sizes I can get to make it from. I don't know if you'd be able to move the sump you have at the minute on and use one of mine, which is another option.

the MO sump if I can't use it would be sold on ebay or if anyone on here wants it I would be willing to sell but I would want what I paid for it. 

I  would be happy to trial one of your sumps :i-m_so_happy:

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1 hour ago, Snagger said:

Cutting and welding would work, but it's got to be easier and more reliable to fit a spacer, even if that means the GKN sump is in the way if you need to drop the 230 sump.  Given the expense of the GKN and its oil issues, and the expense you've gone to with the new sump, it'd be a shame to lose that little bit of capacity and run the risk of cracks and leaks.

I think a spacer is another option to VB's proposed sump, I'll have a better look next week to ascertain how deep a spacer will need to be to prevent the GKN sump & TB sump hitting each other. 

just a shame that MO hasn't looked at non USA vehicles & options to enable fitment to vehicles like ours with the LT230 big sump & a OD.

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Just thinking. A spacer will push it closer to the exhaust. It isnt far away already, theres not a lot of room there. 

 

Will it fit triumphs and the like that use these gkn od’s?

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According to the makers webpage it fits ----Deep Sump, Larger than any other on the market.  It will work on J&P type overdrives. 

 

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Wasn't me !

Mo

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2 hours ago, reb78 said:

Just thinking. A spacer will push it closer to the exhaust. It isnt far away already, theres not a lot of room there.

I found that a bit of metal bent round the exhaust and secure with 2 exhaust U-clamps worked wonders for oil temperature / radiated heat on the ambulance

IMG_4098.JPG

This was very rough just to test the theory.

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Not had chance this evening to try any measuring for a spacer, 

overdrive seems to be working OK,  it did slip initially when moving off from traffic lights on a hill when road tested yesterday & did slip on move off this morning on a level road, but seems to be working ok during driving [OD not engaged] & operated fine when selected in on a nice long section of road, need to checkk/topup the oil tomorow afterwork, couldn't do it today due to change in weather & no undercover work area.

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Ralph,

The OD did have a history of slipping and as a result it had new brake / clutch material & new springs, filter etc. 

Last time it was used it was under Mo's truck and was fine all the way down through Europe for approx. 1k miles. 

It slipped a little when one day and we discovered it was leaking atf from around the solenoid, so for safety sake, we removed it for the remainder of the trip as the atf was low and we didn't have any to hand. (Or a way of sensibly sealing around the solenoid.)

As discussed with you when selling it to you, it hadn't been used since then and I have no reason to suspect anything was wrong with the drive.

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