'03 Baja Transmission questions

[Chris Walden]

I bought this Baja a few years ago. It has an awful noise/knock coming from the transmission, and I'm preparing for a DIY rebuild on a shoestring budget. My experience in a shop comes mostly from rebuilding 350 chevys when i was a kid, and have little experience with trannys/gearboxes/drivetrain.

 

My questions are:

 

How interchangeable are Subaru transmissions? I've noticed there aren't many Bajas in junkyards, and am wondering if I salvaged a gearbox from a Legacy or Forester would work? or even the smaller Impreza?

 

the engine is an EJ251, transmission TY754VCDCA.

 

Thanks.

[bheinen74]

I am new to the BAJA world too, but from what i see, they are based on the Outbacks 2000-2004 Outbacks to be specific.

I would say best to stay with those years. Yeah they continued the Baja for 2 more years past Outback era because they had enough demand of them. they actually hacked some Outback wagons at the factory to make into some Bajas when the supply was low on the lots, I want to learn more but I am not expecting to keep mine, i bought it to flip since i have lost my job.

[ShawnW]

I think I would search car-part for a used one with low miles. They tend to be pretty tough when the fluids are serviced. Banging could be as easy as the front differential being bad and those are pretty easy bearings to change out.

[bheinen74]

also, it appears that noises and knocks are sometimes misdiagnosed, but are real symptoms of Axles that are bad, or even wheel bearings, so first eliminate those items before spending on a trans replacement.

[nipper]

I bought this Baja a few years ago. It has an awful noise/knock coming from the transmission, and I'm preparing for a DIY rebuild on a shoestring budget. My experience in a shop comes mostly from rebuilding 350 chevys when i was a kid, and have little experience with trannys/gearboxes/drivetrain.

 

My questions are:

 

How interchangeable are Subaru transmissions? I've noticed there aren't many Bajas in junkyards, and am wondering if I salvaged a gearbox from a Legacy or Forester would work? or even the smaller Impreza?

 

the engine is an EJ251, transmission TY754VCDCA.

 

Thanks.

 

This may be like replacing the engine because of a fouled plug.

 

how many miles?

When does the knock happen?

Is it a knock or a bang?

[Chris Walden]

138k miles. I replaced the axles about 4k ago, along with boots.

 

the knocking happens when the car is moving, and gets more frequent and louder as speed increases. It's worst is when accelerating. It's also getting more pronounced as the weather is getting colder.

 

I think "differential" sounds like what the mechanic told me - I can't find the estimate. I trust his judgment, but don't have the $$$ to pay him to do it. So it's me, with tools and knowledge I don't have. It's going to be a fun project.

[ShawnW]

Pull the drainplug out of the front diff and check for metal on the drain plug. Post a picture of it if you can.

 

Does this mechanic know Subaru's?

[nipper]

Is this a manual?

 

Either way get a second opinion. A diff doesnt knock it usually wines, but if the output shaft is bad it may knock.

 

Other possabilites tranny mount or driveshaft. The car has the right mileag for the mount, but low for the driveshaft.

 

Look at the dipstick to see if there is material on it.

[idosubaru]

138k miles. I replaced the axles about 4k ago, along with boots.

where did the axles come from? aftermarket axles are notorious for causing issues. i'd suspect bad DOJ on one of the axles if they were aftermarket axles (new or rebuilt, doesn't matter)

 

here's an example just in the past week:

http://www.ultimatesubaru.org/forum/showthread.php?t=118721&highlight=axle

 

happens all the time.

 

driveshaft can cause knocking too if the ujoints or carrier bearing and going bad.

[bheinen74]

how long has the knocking occurred?

before you replaced the axles did it knock?

did it get worse after the 4k mile ago axle job?

what brand axles did you put in? they are notoriuos for being bad right out the box unless they come from Subaru. Most us find the parts store ones to knock right out the box and shake and be bad from the day one.

 

"Don't trust any mechanic" if they are not familiar with Subaru.

[Chris Walden]

So many questions. I like it.

 

I'm not sure the brand on the replacement axles, but I'd surprised if they were OEM. The noise started before the replacement, and the new axles did nothing to improve/worsen the noise. I even drove to Michigan and back since then (yes, rattling all the way). The last few weeks it has gotten very bad, making wonder if the cold is affecting the sound or accelerating the deterioration of whatever is bad.

 

I cannot speak to my guy's exp with Subaru. He's an all purpose guy I've been using for years on projects that I can't do. He may be wrong, but certainly not a crook.

 

You all have me thinking about some stuff though, but I need to get under it to answer a few questions. ie, you've got me thinking about u-joints. I do tend to believe it's more in the axles or bearings than the gearbox, since the noise is more consistent with speed than RPMs. I'll climb under it shortly and get a report on u-joints and drainplug.

[nipper]

We all missed the obvious place to check first, the exhaust hangers.

 

Blu bangs alot, but due to the lift and the trailer hitch, I had to loose an exhaust hanger to clear everything.

 

And don't rule out the axles yet. How is the idle is it smooth?

[bheinen74]

also could be tire noise try to rotate them front to back see if the problem changes where it seems be from

[Chris Walden]

differential oil looked good, and clean. u joints felt good too.

 

It is certainly not a tire or exhaust issue.

 

I had the problem before replacing axles. it has just recently become un-drivable.

 

ultimately, I am likely to get a used transmission from a yard, and either pillage it for parts or replace this one altogether. I can't find a yard with baja, so I need to know which (if any) models have similar enough transmissions to be interchangeable. I'll grab some OEM axles while I'm at it.

[Suba9792]

google gear hack, there is a link for subaru transmission codes, as long as the ratio is the same as yours you should be fine, you could use an OB or legacy tranny as well. I think... check out the site.

Edited December 29, 2010 by Suba9792

[johnceggleston]

check the link below for your ring and pinion final drive ratio.

 

it will be the same as outbacks of similar years. your trans should be the same as others 00 - 04 as long as the final drive is the same.

 

in the late 90s the legacys and outbacks had different ratios. but at some point they changed that and i think they are the same for your year, but you will need to check.

 

you should be able to use any 5 speed from your model year group, 00 - 04, as long as the final drive matches.

 

http://opposedforces.com/parts

[Chris Walden]

I'm finally going to pull the tranny today. based on other threads (like this one: http://www.ultimatesubaru.org/forum/showthread.php?t=56081) I'm betting the differential is screwed. If that is the case, my junkyard replacement should match diff gear ratios, correct? also, I've noted many transmissions have a lower gear ration for 5th gear than my Baja. Would it be as simple as replacing those gears to improve fuel economy? And finally, If i can only find a diff with a different ratio, how would that affect the car? would i need to change the rear diff to match it?

 

Thanks for your help.

[bulwnkl]

And finally, If i can only find a diff with a different ratio, how would that affect the car? would i need to change the rear diff to match it?

 

Thanks for your help.

 

You CANNOT run different diff ratios front and rear, at all, no matter what. You'll toast the center diff (the limited slip section, at least) very shortly if you try. So, if for some reason you chose to change trannies/diffs such that you had a different final drive ratio, you'd want to buy the rear diff out of the same donor car and replace it, too. Gotta keep the ratios the same front and rear.