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reb78

GKN Overdrive Strip Down

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Is there a way of testing spring compression forces easily? 

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I don't know, there is no spring info in the booklets that come with the overdrive, Devon 4x4 might have the specs. 

I won't be doing anymore to the unit until 14/15 June as I away on detachment with work for all of next week. 

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Posted (edited)

I was trying to get my head around Neils idea of spacing the springs last night. If their resting length is the same as the originals, wouldn't spacing them have the effect of making the clutch more difficult to engage in one direction? I cant quite work out which!

GKN would have had the specs once, but goodness knows if they would be able to find them now if you asked and could find anyone helpful there.

Edited by reb78

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My assumptions were basic Rich....

If there is no hydraulic pressure, the OD won't engage.

Therefore the normal / default drive mode must be reliant on the springs holding the brake/clutch cone firmly in one position (locking the sun gear and annulus) and that state being changed when the hydraulic pressure forces the brake/clutch cone into position on the opposite surface (Sun gear locked stationary - forcing drive through the planetary gears / changed gearing)

The hydraulic pressure is quoted to be over 400 psi, so should overcome the springs quite easily, even if the spring rate is increased.....

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bought a 1 inch AF OE spanner, a few minutes meeting with Mr angle grinder it got slimmed down on one side of the open end face & now fits between the OD body & solenoid, which was removed & inspected, looked very clean, but gave it a blast or 2 with brake cleaner, no nasty gunk in the port it occupies either. so this bit is looking fine. solenoid works everytime it was switched on/off too. 

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Posted (edited)

Pretty sure they go under the long allen bolt heads in the casing. 

 

Eta - £4.79?!?! D44 need to get a grip on their prices!! If you can get bits from Overdrive Repair Services they are always a lot more reasonable!

Edited by reb78

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But overdrive repair don't list some of the items Devon4x4 show, they certainly haven't got the springs listed.

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Posted (edited)

No I know but due to D44 prices, if ORS stock the bits I will buy from them. 

Having said that, I was shocked how cheap the springs were in D44! That seal in the link though - if its the one i think- is about 10mm in diameter so how they justify that price is beyond me!

I will cut my own gaskets next time!

Edited by reb78

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I priced up the parts & inc 4 springs & 2 piston seals it was over 84 quid before vat & postage,  making new gaskets at home would be a good move.

ODR have a gasket set listed for the Jtype OD, so no idea if its the same as the GKN gaskets.

 

found this near me https://www.ramgaskets.com/ might ask about getting a set or 10 of each gasket made BUT that depends on what the cost would be.

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Yep. Dependent on price i could be interested in splitting that. I have a full set here we could send to them as templates. 

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Sounds good, they would certainly help, I'll contact ram gaskets when I'm able to. working away next wek.

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On 6/9/2019 at 6:42 PM, western said:

I priced up the parts & inc 4 springs & 2 piston seals it was over 84 quid before vat & postage,  making new gaskets at home would be a good move.

ODR have a gasket set listed for the Jtype OD, so no idea if its the same as the GKN gaskets.

 

found this near me https://www.ramgaskets.com/ might ask about getting a set or 10 of each gasket made BUT that depends on what the cost would be.

Just spoken to Ram Gaskets, yes they can make more gaskets but would need material type & measurements, 

Reb78 you have a PM

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