TH400 to 6L80 swap questions....???

[ballencd]

I've got a 1984 M1010 military ambulance (K30 chassis) with a 6.2 diesel and a TH400 transmission. I am in the process of swapping the TH400 trans for a 6L80 and having trouble getting the TH400 dipstick pipe installed in the 6L80. Anyone done this before? I have bent the lower section of the pipe to line up with the trans but I can't, for the life of me, get it to go into the transmission. Is there a trick that I am missing? Also, How deep in the 6L80 pan does the dip stick need to go to measure the level correctly? The distance from the grommet to the bottom of the pan is quite different between the two transmissions. Attached are some pictures with the measurements. I'm needing to know how deep the fluid is in the 6L80 pan when full and if the TH400 dip stick will work or do I need to find a 6L80 tube and dip stick? Any help would be greatly appreciated. Thanks

 

[Bextreme04]

I've got a 1984 M1010 military ambulance (K30 chassis) with a 6.2 diesel and a TH400 transmission. I am in the process of swapping the TH400 trans for a 6L80 and having trouble getting the TH400 dipstick pipe installed in the 6L80. Anyone done this before? I have bent the lower section of the pipe to line up with the trans but I can't, for the life of me, get it to go into the transmission. Is there a trick that I am missing? Also, How deep in the 6L80 pan does the dip stick need to go to measure the level correctly? The distance from the grommet to the bottom of the pan is quite different between the two transmissions. Attached are some pictures with the measurements. I'm needing to know how deep the fluid is in the 6L80 pan when full and if the TH400 dip stick will work or do I need to find a 6L80 tube and dip stick? Any help would be greatly appreciated. Thanks

Do you mean 4L80? I have so many questions if you are, in fact, trying to install a 6L80. Mainly... why would you do that?

For a 4L80, you would put the dipstick in the tube and mark it to have full at the pan rail. The dipsticks are notorious for being marked wrong on the 4L80.

 

[ballencd]

Yes, a 6L80. It's a slow truck and I needed it to accelerate to highway speeds without losing momentum and the 2 OD's with closer gears looked like the way to go. I have the transmission and transfer case installed but I can't get the dip stick from the TH400 to go in.....any suggestions with that is what I am after. Asking why I did what I did is a moot point at this time. I am open to other input like what aftermarket dip stick would work or even going with a plug if I can verify the fluid level in this without the factory "no dip stick" level check port on the bottom of the transmission pan. Has anyone got experience with this?

 

[goldpack]

Mr. Genius = @NickTransmissions

any ideas? for @ballencd the original poster....

 

[ballencd]

A transmission Genius would be a great help! The trans has only the dip stick hole in it, no threaded fill level plug and no hole in the pan for level checking. Here is the label on the trans if that helps.

You must be registered for see images attach

I can come up with a bunch more questions as this project moves forward but I am stuck here.
Thanks

Charlie

 

[goldpack]

he typed on this long thread he started 2 days ago, but has not signed in here for ~ 6 weeks

https://www.silveradosierra.com/threads/gm-6l80-transmission-information-thread.753826/

if you join over there, make sure to state that you have your Cucv pickup in your garage etc.
...as suburban based discussion lands in the "tailgate talk" section. (as its not a full sized gmc pickup)

 

[NickTransmissions]

@ballencd - buy a 6L80 dipstick.

 

[peats]

Would a diesel trans have a different torque converter and lower shift points due to a different power range vs gas??