Are you looking to install one someday?

 

I would like to at some point but after reading about the GV unit and it can only be used at 30 MPH and above and having a T18 stick with granny low it would not work for the way I would like to. Like start off in granny low OD so you don't have to slip (read wear out) the new clutch to get going like if starting in 2nd, then shift to 2nd direct and so on.
I also under stand that gear ratios between direct & OD can be so close it is not worth "splitting" every gear going up or down.
Also if stuck in traffic I could maybe use the granny OD and creep along and not need to ride the clutch as much.

Because of the 30 MPH deal I would most likely go with Advance Adaptors Range Splitter. You can use it at any speed and in any gear but think it is only for stick tranys.
It is the only one I know that will work in 4x4 as it sits between bell housing and the trany, I have a 4x2 so not a big deal there.

Then again I need to get the truck on the road and see how it does with the 300 six & 2.75 gear out back. With any OD unit I am sure I would need to go to a lower gear maybe 3.55, think 4.10 would be to low for me.
Most of the time my truck will not have a load other than a few bags of trash to run to the dump each week. It will also be a backup to pull my car trailer and that is when the granny gear would be real handy and then OD.

Yours is the first I seen in a 4x4 and why the "adaptor" looked strange to me.
I also like to hear how others did on the install both GV and AA RS, any issues? and how they like it out on the road.
I know of some guys that have GV in cars and love them. I installed a 5sp with OD in my car but also have not had it on the road ye,t but math says it should do good.

On the drive shaft with the bearing check with the shop and see if you even need it now. It could be the shaft is short enough that you can go with a 1 piece and no bearing.
Other wise from the bearing back to the axle should be the same only from the trany / OD unit to bearing has changed is this now too short?
When you measure make sure the truck is sitting on all 4 wheels, weight on suspension.

Keep us posted when you get it on the road.
Dave ----

 

At some point I would like to but would go with the Advance Adaptor Range Splitter.
The GV you cant use below 30 MPH and I would like to be able to split the granny gear if needed, I have a T18 with granny low 300 six & 2.75 gear out back.
Being a six having different split ratios would be nice but I need to get it on the road before doing an OD unit.
The AA RS I think is only for stick tranys, fits between bell housing & trany so can be used in 4x4's and used in any gear at any speed.

I just like to see what others have done for OD units, issues they may have run into, etc.
Yours is the first I seen in a 4x4 and why the question on the adaptor as I never seen one before.

As for the drive shaft check with the shop as you may not need the bearing.
Is the shaft between the GV and the bearing too short now?
The other part should not have changed right?
Dave ----

 

Actually that's only if it's in automatic mode. In auto mode all it does is add an extra top gear that automatically engages at ~43mph.
If you set it in manual then it's a gear splitter that gives you 1st OD, 2nd OD, etc. By default it's done via a dimmer switch you mount on the floor.

I never looked into the AA unit (this is the first I've heard of them admittedly) but having it work in 4wd would be nice so you never have to worry about what if the gvod engaged somehow while in 4wd. I am going to have to google that unit as I'd like to see how it goes before the transmission.

Regarding the install, the gvod is about as simple as it gets. Even more so for a 2wd. I've got a second gvod that I'd like to put behind my 400 T18 but need the adapter. With the adapter all you have to do is remove the existing tailhousing/mount, replace it with the adapter that has a mount built in and then install the od behind that.

For the driveshaft I think one could do away with the carrier bearing and have a new driveshaft made to go from the od to the rear end BUT my truck is a super cab so I'll just need to shorten the front section and leave the rear section alone. I think the gvod manual explains how to measure with a carrier bearing so I'll check it out when the truck gets further along.
The parts truck that has the other gvod in it is a super cab also but it's a 6.9 T18/19 so I doubt I will be able to use the front-half driveshaft from it.

 

Here is a link to the AA RS http://www.advanceadapters.com/categ...-splitter/236/
And as I thought only for stick tranys. So if you have an auto the GV is the only way to go for an OD unit that will also work with a stick trany.

I did not know you could run it manual and split the gears even under the 30 MPH that I have seen posted.
I have heard of guys over riding the speed part but thought it was a no no from GV.
Dave ----