A new product for the GMTH400 transmission

[chris718]

After reducing front end play ,grounding the direct drum,supporting the backside of the drum with a Delrin shim ,and putting a bushing in the front end of the direct drum I began to see improvement in the areas these modifications were meant to improve.The dividends paid in results were still not enough.The continued ,but greatly improved upon related losses in third clutch and intermediate sprag performance have resulted in the next,and possibly final modification to this area.The next part is in the form of a CNC machined E4140 sun gear shaft that introduces a tight press fit between the drum and the shaft.I thought about doing this before but didnt settle on it because of the fear of material choice,the work involved ,and simply the fear of the unknown.After speaking with Hutch for Hutchinsons Transmission Service in Canada a few months back and getting the right information to extinguish the fears I had on the parts they are complete on my end and just need to be sent out for finish grinding.If in fact direct clutch seal ring grooving from drum oscillation and the losses in third gear performance as well as reduced sprag capacity and failures are caused by or exagerrated by the non existence of the tube ,then we will now see a tremendous improvement in the peerformance of all TH400 transmissions we install it in.

 

[turbobitt]

Chris,

Can this be installed on any drum ? If so, I would like to try one.

Allan G.

 

[chris718]

Yes any 400 or 4l80 drum Allen.

 

[bluchev]

how much?

 

[turbobitt]

Yes any 400 or 4l80 drum Allen.

Put me on the list for when these are complete.

Allan G.

 

[cruzn57]

1st....

I know little about T400 workings, or any other auto trans for that matter.

does this reduce slop (for lack of a better term) in the 3rd gear clutch, and sprag?
will it help stop sprag rollover?
or is it a closer tolerance part.

I guess what I mean is what benefit is it for my T400 ( full manual)
Thanks

 

[chris718]

The benefits are improved clutch life and sprag performance.This is the part that will give the sprag the perpendicularity and parrallellism to the rest of the trans it needs to run true and on center to reduce side loading etc.

 

[quickt]

Nice piece Chris.

 

[chris718]

Parts are complete,and in stock. Contact me for pricing.This is a limited edition run.I am extremely happy with the finished product.New item coming shortly,billet aluminum direct drum w/steel sleeved seal ring bore and pro mod sprag.Materials in,job is being set up.

 

[turbobitt]

Parts are complete,and in stock. Contact me for pricing.This is a limited edition run.I am extremely happy with the finished product.New item coming shortly,billet aluminum direct drum w/steel sleeved seal ring bore and pro mod sprag.Materials in,job is being set up.

Chris, Will call tomarrow.

Allan G.

 

[chris718]

Here is the finished product.

 

[Alky V6]

Very interesting, Chris. I look forward to trying it out.

 

[chris718]

Every so often we will find a drum with enough wear the press fit is on the loose side.Be awake when selecting a drum.

 

[turbobitt]

Chris,

I have some feedback I would like to give you.
Allan G.

 

[chris718]

allen give me ring .im up for another hour 718 506 6465

 

[chris718]

' I anastasis tis solinas" Translation "The resurrection of the tube." Fitting to bring it back around the easter holiday.Yes,linked it up from YB.