4-speed tail shaft

-

Kegan B

Well-Known Member
Joined
May 17, 2011
Messages
2,994
Reaction score
1,073
Location
IN
Can the earlier flange style tail shaft be converted to a slip yoke on a 4-speed? Thanks.
 
yes but you need a different mainshaft and tailshaft housing. The main case is standard mopar. The gears and input shaft are usable as a set. put it in 1st gear and check to see what ratio is. alot of trunion 4 speeds have a 3.09 1st gear. trunion mainshaft and tail shaft are boat anchors.

Two parts required for 30 spline (727) standard slip yoke conversion.
1. http://www.brewersperformance.com/proddetail.asp?prod=MS-909R
2. http://www.brewersperformance.com/proddetail.asp?prod=EH126
cost for 30 spline conversion 400.00

all other parts in a trunion 4 speed are standard mopar. Here is cheap way to pull it off using 26 spline (904) yoke

1. http://www.brewersperformance.com/proddetail.asp?prod=MS-920
2. http://www.brewersperformance.com/proddetail.asp?prod=EH706
cost for 26 spline conversion parts less than 200.00
 
. main case, gears, and input shaft are all the same..

I'm not sure what this means or that it's even true. Input and gears out of a 3.09 box are certainly not the same as other gearboxes, nor is the mainshaft
 
A trunion 4 speed is a parts donor unless you need it for a resto. You put a standard non ovd mainshaft in it with a standard slip yoke tailshaft and you get a regular old mopar slip yoke transmission. some not all trunion 4 speeds were 3.09 ratio 1st gear. the input is not the same it is 3.09 to 1 ratio. you have to use them as a set to match counter shaft. I will put it another way. If you remove the trunion mainshaft and tailshaft it is a matter of replacing them with a standard mainshaft and tailshaft.

just FYI 67dart273 2nd pitch design overdrive 4 speed is 3.09 1st gear and so are some trunion 4 speeds. what this means is the input shaft will interchange between the two and they were made 20 years apart. http://www.brewersperformance.com/proddetail.asp?prod=IS-OD22&cat=261
the only difference that you will find on a trunion is a oil slinger on the input shaft. I asked wayne at brewers about this and he said pitch the oil slinger. Back to original ? changing a trunion over to non trunion is simply a matter of swaping out the main shaft and the tailshaft along with a good rebuild kit. just call passon or brewers and tell them what you have and what you want to do and they will supply you with the needed parts.

I edited my earlier post and gave links to required parts.
 
I'm going to have to check but here's what I remember.........

When I put the Advance Adapters shaft in my old Landcruiser, I wanted to use a 3.xx low gear and their shaft would not fit a 3.00 low gear because the main shaft was smaller? in a 3.xx low gear?

Or am I confused and thinking only of a OD box?

By the way, those Advance Adapters shafts were real POS too bad I didn't know it at the time

(A833 to Jeep transfer case) Too much shaft end play tears up the 3rd gear, and the shafts are soft, wears out on the Jeep drive gear end.
 
You will also need a new speedo cable. I found it easier to replace the whole 833.
I got lucky and found an 833-od iron case. Of course then I had to replace the bell and pivot and fork and ... well maybe it would have been easier to replace the tail but then I couldn't have gone with the larger clutch.
 
I have a a-body cast iron ovd unit if you want another one lol. ovd gears are their own mutt.
 
-
Back
Top