Differences between GV and Laycock OD

[ocnorb]

Picked up a Laycock P-type overdrive for a good price today. Thinking about swapping it in place of the Gear Vendor that no longer engages in my '86 F350. (I really miss the OD) Externally it looks exactly the same. The PO says it came out of an '89 GMC with a 4-speed trans. It looks like it might bolt up to a NP205, but I'm not sure. (Just went to look at it closer and it does say "GV 205" on the casting!! Score!)

Are there any internal differences between the Laycock and GVO?

Any down side to just swapping it out?

I will also swap the big oil pan from my burned up unit to this one.

Another thought was to tear them both down and build one good one from the two. I've heard that the old clutch material is tougher than what GV can currently offer due to EPA/Cali restrictions.

I do know that I have to turn this around pretty quickly as I promised the wife it would be at least a break even deal- gotta pay the piggy bank back.;p

 

[greg_a_morton]

the laycock is the original style units from overseas. I call mine a gear vendor but it is a laycock also. All parts are suppose to be interchangeable. If you swap them out what do you want for the non op unit?

 

[crashnzuk]

Just as an interesting side note, I looked at one of my co-workers GV units that is sitting here and it says Gear Vendor under/over drive assembled under license from Laycock Engineering.
Travis..

 

[greg_a_morton]

gear vendor has bought full rights to all there stuff now from what I understand.

 

[ocnorb]

the laycock is the original style units from overseas. I call mine a gear vendor but it is a laycock also. All parts are suppose to be interchangeable. If you swap them out what do you want for the non op unit?

Not sure yet. I would like to take a look in it and see what broke... curiosity more than anything.

Some sources on the web claim that the GVO has a larger shaft size -1.375" if IRC. Any truth to this?

How hard is it to find a C-6 to NP205 adaptor and install it?? This has me seriously considering making the truck a 4x4.

 

[icanfixall]

Gear Vendors and Laycock are one and the same. They have been installing these od units in Austin Healeys since the mid 1950s. Volvo has them as do Triumphs. The late design is called "P" type and is much better than the "J" type of early years. Robert will chime in on more info shortly on these od units. He knows his stuff far better than the rest of us.

 

[Diesel JD]

Yeah also of note, I found a site in the UK that still sells Laycock units. They seemed like they might be a little cheaper than GV units but that might not be the case once you converted the currency and paid all the shipping and so forth. It would be interesting to see if you could throw that thing on there. I bet you could, because the main thing stopping most people from doing the same is not having the adapter to do it with. GV will not sell them outright, but you already have a non operational GV with the correct adapter and a good laycock unit that probably would bolt up to that adapter. I've always been under the impression if you could get or make the correct adapter any Laycock OD that is strong enough for an IDI becomes an option, and if Robert does chime in I'm sure he'll let me know if I'm correct or incorrect in this assumption.

 

[rjjp]

How hard is it to find a C-6 to NP205 adaptor and install it?? This has me seriously considering making the truck a 4x4.

4x4 C6, the output shafts are different between 2wd and 4X4... but a divorced transfer case is an option.

 

[RLDSL]

Yup, just grab one out of a late model Volvo 740 with an M46 4+1 manual trans and you will have a P type that has the stronger cone clutch material than the GV has ( the earlier volvo 740 and 240s had the j type laycock units hooked uo to their M46 boxes those were the units that GV originally used but had a GCWR of 16k attached to them, which still astounds me, not nears as much as what they claim the new units will pull considering the cone clutches are weaker than the volvo units, if I were going to go the GV route, I would for sure buy a dead one to get teh adapter and then get a volvo unit and give it a fresh set of orings and then go with it)

Somewhere around here I still have a rebuild manual for those things. I've rebuilt enough of the blamed things. Really a fairly simple beast.
If you had one that wasn't engaging, chances are teh orings in teh solenoid were shot. You can get new orings for the insides of teh solenoid and rebuild that sucker and stop the internal leaking to where it builds pressure internally again and will engage, costs about $5 as opposed to near $100 to get one from GV

 

[RLDSL]

Not sure yet. I would like to take a look in it and see what broke... curiosity more than anything.

Some sources on the web claim that the GVO has a larger shaft size -1.375" if IRC. Any truth to this?

How hard is it to find a C-6 to NP205 adaptor and install it?? This has me seriously considering making the truck a 4x4.

I've never heard of any differences. There used to be a guy on ebay who was refurbishing laycocks and aquiring GV adapter housings and selling them but I think GV shut him down because I havn't seen anything from him in quite some time. GV likes to keep a tight rein on ALL adapter housings out there, they don't like anyone actually *owning* the things and doing what they want with them that's why they refuse to sell you an adapter outright unless you have an old one to trade them, because they don't want folks grabbing laycock units and making their own

 

[RLDSL]

That said, I've got a few old laycock units laying around I could measure once I get over this stinking cold i have right now which has me down for the count

 

[ocnorb]

If you had one that wasn't engaging, chances are teh orings in teh solenoid were shot. You can get new orings for the insides of teh solenoid and rebuild that sucker and stop the internal leaking to where it builds pressure internally again and will engage, costs about $5 as opposed to near $100 to get one from GV

Went through all the easy stuff; found that the screens were clean and the solenoid was engaging. Symptoms seem to point to a bad cone clutch. I have a lead on a guy in Califorina that can and does sell individual parts and adapters. If it works out I will post his info for all here.

 

[greg_a_morton]

call Glenn at Maximum overdrive he will be able to get you any thing you need to get.
http://cgi.ebay.com/ebaymotors/GEAR...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

[greg_a_morton]

gear vendor will sell the adapters without a core but the cost $200-$250 more.

 

[RLDSL]

Went through all the easy stuff; found that the screens were clean and the solenoid was engaging. Symptoms seem to point to a bad cone clutch. I have a lead on a guy in Califorina that can and does sell individual parts and adapters. If it works out I will post his info for all here.

Even when teh solenoids are clicking , that doesn't mean they are working on these things. THey have these little tiny orings on a shaft that goes up inside the stem that you can see , the internal removable shaft has a couple of orings on it and when those start leaking it doesn't matter how much that sucker clicks, it won't hold the pressure internally and won't engage. Leakage at the external orings that you can see will cause it to fail as well

Most of teh failures on these things are hydraulic. first the solenoid orings, then the main pump orings( a series of orings in 3 chambers in the main compartment.) last on the list are hard mechanical failures like teh cone clutch burning out or the gears or little spring retainer bar do hicky assembly getting mangled. Those generally happen when shifted into OD at too low speed or in reverse repeatedly or while downshifting and too low, generally not supposed to be a problem with the GV electronics that are supposed to prevent that from happening, but epidemic on European cars where they are all manually controlled

I've got a regular supplier for parts for those things in Kansas City, but if you have found someone who is selling adapters without requiring a trade in, please, do tell. I've been thinking about taking one of my spare units and using it on a car project and might need one of those divorced install adapters