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Help with ratio issue using D/R & 3.9 in a 5 lugged Loyale


machthree2
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Please any advice. Picked up a great little 91 Loyale which had an EJ conversion, 5 lug and a swap of the original 3AT to a 5 speed D/R. There is a definite ratio issue when in 4 WD. Can't even drive the car on dry pavement, and on Dirt it is almost impossible. On Snow you can definitely tell that the front and the back are going a slightly different speeds and it make the front wheels lose traction and steering. Making this car pretty useless in snow? 

 

It has impreza FWD CV's with Legacy Knuckles on Front, and stock CV's and XT6 rear hubs. 

The splines counts are strange on front to back. 23 - 27 front and the rear are 23 - 23 to the stub and then using the XT6 hubs. This car shows a 3.9 rear diff ?

 

Can't hardly get the car out of 4WD without backing and jamming lever? Need advice if have any.

 

I'm wondering if the original AT tranny was a 25 spline and the rear 3.9 diff is different. Or having the spline differences are causing the off ratio?

 

Help

 

thanks 

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Rear diff cover may have 3.9 on the sticker but the gears inside may not be. You'll have to turn the driveshaft with a wheel jacked up and count the turns. Does the dual range trans have a FWD position? Or is it just high and low? A full time 4x4 dual range could have a 3.7 front diff in it, but then it should have a vacuum can on it to run the center diff lock.

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I believe '85-'86 RXs had a part-time 4WD with a 3.7. However that would have 25 spline stubs.

 

 

I'm not sure what you're getting at with the spline counts. That doesn't really have any direct effect on the gear ratios. The 23-spline stubs on the transmission indicates it's probably (it's possible to swap them, but they probably didn't) a non-turbo transmission, which means it's almost definitely a 3.9.

 

Which means it's most likely that the rear diff cover doesn't match it's internals (3.7 w/3.9 sticker).

 

 

It'll be difficult to see the difference between a 3.7 and 3.9 by counting driveshaft rotations. Probably easiest to double it. Mark the driveshaft. Raise one rear wheel, spin it all the way around 4 times (with other rear wheel on the ground, the spider gears will halve it for 2 rotations of the ring gear). The pinion/driveshaft should rotate either 7.4 or 7.8 rotations, should be easy to tell if it stops less than 180* from where it started, or more like 270*.

Edited by Numbchux
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Thanks Numbchux

 

I was thinking that the OD on the outer CV 27 spline might be bigger so bigger diameter? But I guess that wouldn't make any difference on hub rotation relating to transmission rotation. 

 

I'll check the shaft to wheel rotation when the car is here later tonight. Thanks for the advice. 

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Do all 4 tires match?  Same size? 

 

Any D/R 5spd with 23 splines (that hasn't been modded) should be 3.9 so should match rear diff.

 

There are 3.7 single range trans in Non-turbo xt with 23 splines.....but no D/Rs. 

 

You could take the cover off the rear diff and count teeth on the Ring + pinion gear.  39/10 is 3.9 

 

You shouldn't really drive in 4wd on pavement at all.

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All Four tires are Exact. Good call. 

 

I don't typically drive in 4wd on dry. I have had Loyale's with push button and also an 88 turbo with a switch, and had no problem driving them on dirt or snow / wet conditions. You can definitely feel a driveline strain on this thing? Since I don't have experience with the Dual Ranges, I recently took a Brat for a test drive. Put the thing "temporarily" in 4 high and it was smooth as silk on dry at 5 to 10 mph. Just a quick test to see if it worked. Could definitely tell that it worked. If I put this well built Loyale into 4wd on dry, it won't even move. 

 

I will test the driveshaft to wheel rotation (multiple turns) to see if I can tell. Thanks for the post..  

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OK -  Did the test. The driveshaft did 7.8 turns or stopped at 7 3/4 (270)  -  Back to square one. 3.9 

 

front Impreza FWD front halfshafts on Legacy Knuckles/hubs -  rear is XT6 hubs and (disks I think)

 

Was there a JDM D/R from Japan that has different ratios. This car had a 3AT in it previous to the 5 speed D/R.

Still Lost.

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So.....the trans you are using.........do you have an adapter plate for it?  Or does it mate directly to the EJ engine?

 

I would pull the transmission drain plug.......mark the ring gear and start counting teeth by rotating it until teh mark comes back around.

 

the number of teeth will give you a clue, but not a definative answer which ratio it is.......since the pinion # of teeth is part of the equation too and thete is no easy way to count those in the car.

 

39/11=3.545 (SVX)

37/10 = 3.7 (RX, XT, Turbo GLs)

39/10 = 3.9

37/9 = 4.11

40/9=4.44

 

Based on this, if you get 39 ring teeth, you definately have a 3.9 since no SVX came with D/R and no D/Rs came 3.545 to my knowledge anywhere.

 

Now if you get 37 teeth......you could have either 3.7 or 4.11......could probably figure which by observing if the front wheels want to travel faster or slower than the rear.    Front faster=3.7, front slower=4.11

 

If you've got a 4.11 D/R you are a lucky SOB.

Edited by Gloyale
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Keep in mind, it's a part-time dual-range. To my knowledge, the only options for that would be the '85-'86 RX 3.7 (which would also have 25-spline stubs), or the ever-so-common 3.9.

 

 

I think, if it's not a 3.9, it would have had to have been opened up and modified (at least axle stubs swapped).

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don't know about the adapter plate ... i think it is an SJR .. this is tractorpole's old loyale. i had to get a halfshaft and i got an impreza 1.8 fwd and didn't count splines. i'll go and count the old one. he had a build sheet , may help.

 

i'll check the tranny next .. got a new project this weekend. A stock 86 brat gl with 92 k. the d/r is amazing. 

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  • 1 month later...
  • 3 months later...

i found a couple of ea82 turbos.. Mite buy the 3.7 diff and try it. what should i pay a salvage yard fpr just a diff??

 

he has multiple standard 5 speed d/r with matching diffs but wants 4 franklins for them?

Ouch $400.00 US for a Loyale Dual range with third member, Here In Sydney, Well I can buy any Gearbox from a PIck and Pull for $270.00 AU which is about currently $213.00 US including Dual range LIberty, Legacy Outback or Forester and Forester Dual range boxes in Australia are 4.11 Gears with a 1.4 Ratio Low range stock.

 

Outbacks Liberties and Legacies which here are Jap Import cars are dual range but like the US RX Turbo Loyals with only a 1.1 Low range drop ratio so while better than single range are just a Box to use to modify with Loyal 1.6 Low range gearsets.

Obviously the Australian Forester Gearbox is the one to have for an EJ without building a custom Loyal EJ gearbox if only the freight was cheaper, Well I suppose it is when shipped seafreight and added to somebody elses container.

Edited by coxy
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