EA71 4-speed to EA81 5-speed swap

[Trustyoldiron]

I am attempting (and failing) at trying to swap an EA 71 4-speed engine and transmission for an EA 81 5-speed engine and transmission. I have hit a deadend. Although everyone who has done this kind of swap says it's easy, I'm stuck! I hope you can help. I have nowhere else to turn.

 

Obsticales:

The half-shaft lengths are off because the new transmission is wider than the old transmission.

The 5-speed transmission seems shorter, so I'll have to get the drive shaft extended.

The shifter linkages don't line up. Neither do the transmission mounts.

The engine and bell housing don't fit on the cross member beneath them correctly.

HELP! Your time is appreciated. Thank you!!

Ben

[Pooparu]

Why would you need a drive shaft if it's an EA81 5-speed?

[ShawnW]

What year is the car being worked on?

[Trustyoldiron]

The drive shaft needs to be changed because the transmission is shorter than the original.

The Car is a 1978 Subaru brat.

[Pooparu]

I didn't know ea81's came with a d/r 4wd 5-speed transmission.

[Trustyoldiron]

It’s got a duel-range 5-speed 4x4 transmission paired with the ea81. From what I can tell it seems to be a common set up in the Subaru’s from the early to mid-80’. Right Before the ea82 was launched. The ea82 was paired with the same duel-range 5-speed 4x4 transmission as the ea81 (I think).

 

-Ben

[Leeroy]

Ben the EA81's only came with 4 speed transmissions unless they were 2wd (or automatic of course).

 

I think the biggest problem you will face is the CV joint assembly will interfere with the steering shaft/joint.

 

If you search there is info on the USMB about what is required to modify EA81 (which are the same as EA71) gearbox mounts to fit the 5 speed. Some people cut the 'ears' of the mounts and weld on a new piece which is then bolted to the transmission, others elongate the holes in the mounts and the transmission crossmember to make it all fit. Some (GD?) have even made the EA82 mounts fit with lots of modification (they are a better design). There is also a USMB member called Jerry (IIRC) who makes a kit for fitting the 5 speed in the EA81 engined cars.

 

Note your Brat originally had the EA71, I doubt Jerry's kit will work and there are some clearance issues, the previously mentioned steering problem is the one most come across and I am not sure if the width of the 5 speed creates issues in the transmission tunnel, especially if your Brat is not lifted.

 

I should point out I have not done this conversion myself, although I keep thinking about trying it! The info I have kept in my head from reading through many posts on the subject over the years.

 

Basically while not impossible there would certainly be some fabrication needed to get the 5 speed to fit, not the least of which is;

 

 

• Custom mounts
  

 

• Lengthened drive shaft (or use the EA82 drive shaft by installing the centre bearing mount to your trans tunnel - this seems relatively easy!)
  

 

• Custom shifter linkages or the original 5 speed stuff by modifying the trans tunnel to make them fit
  

 

• Some mucking around with the steering shaft/linkages so it can clear the CV joint assembly
  

Edited October 26, 2012 by Leeroy
extra info

[Pooparu]

I've never installed a 5-speed D/R into an first gen before, but I have installed the EA81 4-speed D/R into a first gen. So I'm not sure of the challenges that creates. I've also done an EA82 transmission into and EA81 & a EJ transmission in a EA81 (not easy).

 

You'll need to swap out the bell housing, flywheel and clutch to the EA82 set up. You can also grind out a notch in the transmission or weld in an extension on the steering linkage to solve the clearance issues, you can ether have a one piece drive line built or use the ea82 drive line and just mount up the center carrier bearing (bolt or weld). Then possibly do a bit of cutting, grinding and welding on the transmission tunnel for the shift linkage and any clearance issues you might have. Then build your transmission mount. From my experience this is what I think you'll need to do. If I were you I'd just put in another 4-speed s/r transmission unless you have the time and money to do this conversion.

[Trustyoldiron]

Thanks for all the advice. I really appreciate it. The engine that came out of the brat has the starter at the 12’0 clock position while the ea81 has it at 11’o clock position (from the flywheel side) so my ea81’s starter and my ea71 starter would not line up. The splines on the clutch half are also different from one another on ea71’s transmission and the ea81’s transmission. The ea81 also bolts right up to the 5-speed duel-range transmission. So to clear things up here are some photos…

 

The EA71 (not mine) http://allenginelist.com/cars/ea71-subaru-engine-specs/

 

The EA81 (Identical not mine) http://2.bp.blogspot.com/_18iKeFSX3CM/SH-kPEA4m_I/AAAAAAAAAJk/K7O4G-f0-HI/S660/subi+engine.jpg

 

The 5-Speed Duel-Range transmission http://img229.imageshack.us/img229/1993/p7011028.jpg

 

I cannot Find a pic of my 4-speed 4x4 transmission.

 

Thanks. Ben