Sub-Frame and Rear Diff Bushings

Ok, So my car is up to 230k now and its due for a rear suspension revamp. I have all of the OE part numbers found for the rear suspension except a few parts, mainly because subaru conveniently doesn't sell the bushings as individual units. (the 4 sub-frame bushings that mount to the body, the rear diff front carrier, and the rear front lateral links)

I don't want to drop $300 just for a new sub-frame to get new bushings

I plan to drop the whole rear sub-frame and really give it some love

So does anyone have some knowledge to help me out here.

1) Are the bushings for the sub-frame solid or like many of the bushings are there holes?

- If so I will fill the voids with 3M window weld and call it a day.

- If not, does anyone know other aftermarket bushings that can replace said bushings.

2) Similar problem with the rear diff cradle. I know I can source a new one for around $60 but I feel just the bushings should just be changed. Thoughts and alternatives?

****2005 Legacy GT Wagon

Thanks

There are Group N bushings for rear subframe for 08+ STI.

I vaguely remember looking into them, but never found out if they fit or not.

Worth a shot.

http://www.rallispec.com/mou_bush_rstbk3.html

The rear diff bushings as well as the diff support bushings do fit.

While the sub frame is out check the gas tank for rust and soon to be leaks.

I had my tank replaced last Aug with a new fill pipe and AEM 320 pump.

Did not even worry about the bushings.

My body shop buddy did the work, good thing, they had to cut the frame to get one of the nuts out because the welds holding it broke.

Max Capacity, thanks for the heads up. I've replaced the fuel filler neck on my 96 outback, didn't realize it was a problem with the 05.

Knock on wood, this car for its age hasn't given me any trouble with rust or seized bolts.

I'll take a look into the Group N bushings. Price is kind of high but might be worth it. I'll keep digging and see what I can find.

The car is in such great condition for its age, it's definitely worth the fresh upgrade and bushings

The other tip is to be careful of the nuts inside the frame rails. Use lots of PB Blaster or invest in Aero-Kroil and let it work over night.

https://www.google.com/search?q=aero-kroil&oq=aero-kroil&aqs=chrome..69i57j0l5.3975j1j8&sourceid=chrome&ie=UTF-8

So I found these part numbers as part of the subrame bushings...I think, but I am not entirely sure of the order they go on or purpose. I can not find picture of it or much description for either.

20176AE01A9E

20176AE06A

Thoughts?

Dose this help ? I don't see exactly the part your talking about, but most dealers will have the same link.

https://parts.suburbansubaru.com/a/Subaru_2005_Legacy-GT-Limited-Sedan-25L-TURBO-5AT-4WD/_54106_6029078/REAR-SUSPENSION-FRAME--STABILIZER-OPC83-06MY-06MY/B13-201-04.html

I replaced my rear subframe bushings (the ones that mount to the body) with the Powerflex PFR69-417. I used a rosebud oxy/acetylene torch to burn/melt them, then pushed the goo out with one of the drivers from the Harbor Freight 10 Piece Bearing Race and Seal Driver Set. Then the metal shell of the bushing had to be cut into sections and chiseled out. Then the installation of the new Powerflex bushings was a piece of cake, just slathered them with Energy Suspension's Formula 5 Pre-lube and pushed them in by hand.

Replacement of these bushings probably wasn't really necessary. The main reason I replaced them was because I had convinced myself that all of my suspension components needed to be powder coated, so it was necessary for me to remove the old bushings because the coating process requires the part to be baked in an oven at a temp that would melt the rubber bushings if not removed beforehand.

As for the rear diff, I installed the Whiteline - Rear diff Positive power front & rear kit (KDT905 & KDT906). I actually managed to bend my subframe when trying to press the old ones out, gotta make sure the lip of the sleeve which houses the bushing, is properly supported underneath. My subframe was damaged beyond repair and had to be replaced with one from the scrap yard. Lesson learned the hard way!

More discussion of the rear subframe bushings can be found in this thread http://legacygt.com/forums/showthread.php/rear-subframe-bushings-254353.html

Ok cool. I am likely going to stick with OE bushings for the rest of the suspension components (unless the poly bushings don't ruin the compliant ride too much)

Do you have pictures of the zerk fittings? You just drilled and tapped the lateral links to install them? I have never installed a zerk fitting so that new to me, but smart way of re greasing the bushings

I just bought some metric grease zerk fittings from a local fastener supply house, I believe they were size M6 threads. Then I drilled and tapped holes in the center of the tube on the end of the lateral links, control arms, or whatever part housed the bushing. The new poly bushings are actually two pieces that press in from either end of the tube and they don't actually touch in the center, there is a small gap between them, this gap allowed for the grease zerk to protrude slightly into the tube and deliver grease to the area between the bushings. It is my hope that the grease will then spread out from the center area to the rest of the bushing. In hindsight I probably should have cut some slots in the bushing to help distribute the grease out from the center. I haven't actually tried greasing any of these yet as I haven't felt the need.

I've attached a few photos that I took during my suspension overhaul, unfortunately I didn't take any directly of the zerk installation, instead they're more general pictures of everything. The fittings can be a little hard to spot because most have black dust caps installed.

Wow, that is a clean set up. Thank you very much for all the information! Very helpful!

Definitely going for the poly sub frame bushings to replace the old ones.

I just bought some metric grease zerk fittings from a local fastener supply house, I believe they were size M6 threads. Then I drilled and tapped holes in the center of the tube on the end of the lateral links, control arms, or whatever part housed the bushing. The new poly bushings are actually two pieces that press in from either end of the tube and they don't actually touch in the center, there is a small gap between them, this gap allowed for the grease zerk to protrude slightly into the tube and deliver grease to the area between the bushings. It is my hope that the grease will then spread out from the center area to the rest of the bushing. In hindsight I probably should have cut some slots in the bushing to help distribute the grease out from the center. I haven't actually tried greasing any of these yet as I haven't felt the need.

 

I've attached a few photos that I took during my suspension overhaul, unfortunately I didn't take any directly of the zerk installation, instead they're more general pictures of everything. The fittings can be a little hard to spot because most have black dust caps installed.

Wow!!

Hey guys, so here is an update. I have the subframe out, luckily no seized bolts...yet. Next up is to drain the gas tank and drop that out. I am going to paint the filler neck while I'm here and check the tank for rust. My 96 outback had the filler neck rust and that wasn't fun to replace so, might as well prevent as much as possible now.

Elgin.owens thank you for the help before. It has really coming in handy. I ordered the poly subframe bushings cause mine are nice and mushy

Then it's por-15 on the subframe, trailing arm and lateral links. Raptor liner is going to be applied to the entire under body

Then new bushings (I have them all and will list part numbers for those interested)

Them installing new shocks and springs. I'm pretty much going to have a new car once I'm done.

I'll update as I go now that I'm underway

Once you post all of your part numbers, I'll put it in my IDEA sticky so if anyone else want's to do what you're doing, they'll have them at hand.

Thanks.

Ok so here is the comprehensive bushing list for the rear end.

https://drive.google.com/file/d/13GDnfLPA_YwQfC05BGwS-lvhJUTNRfH5/view?usp=sharing

Word of advice, if the rear bushings start squeaking....replace them asap. Ask me how I know

I just bought some metric grease zerk fittings from a local fastener supply house, I believe they were size M6 threads. Then I drilled and tapped holes in the center of the tube on the end of the lateral links, control arms, or whatever part housed the bushing. The new poly bushings are actually two pieces that press in from either end of the tube and they don't actually touch in the center, there is a small gap between them, this gap allowed for the grease zerk to protrude slightly into the tube and deliver grease to the area between the bushings. It is my hope that the grease will then spread out from the center area to the rest of the bushing. In hindsight I probably should have cut some slots in the bushing to help distribute the grease out from the center. I haven't actually tried greasing any of these yet as I haven't felt the need.

 

I've attached a few photos that I took during my suspension overhaul, unfortunately I didn't take any directly of the zerk installation, instead they're more general pictures of everything. The fittings can be a little hard to spot because most have black dust caps installed.

Thank you for the help. I am in the tedious progress of cutting out the bushings after burning the worst out. Powerflex bushings fit like a glove, thanks for the advice. Once I am done this I will be painting the subframe.

Yeah I have been debating on truck bed lining the subframe. Not so much the gas tank. The only thing holding me back is that It is winter (so painting indoors) and truck bed liner smells a lot. when I did the underside of my car, the neighbors weren't too happy (I live currently in a row home). Definitely going to brush on por-15. If I truck bed line, it'd be a brush on job to keep down on the mess and smell. The tank is in rather decent condition. There are like two spots where I need to cut off some rust, and por-15 rusty brackets (or replace brackets)

one battle at a time. Right now the battle is getting the rest of the bushing races out. Thanks for the input!

Ok, so I have the bushings removed. What a PITA! There was some minor collateral damage on the subrame due to the fact that is is very difficult to see if the sawzall has gone all the way through the race or not. Also there was a slight curve to the sawzall blades that didn't help at all.

The damage can be seen in a few photos. It honestly looks worse than it is. I am debating on filling in the groove with some weld bead and then grind it smooth or just leave it. I am going to be adding polyurethane calk when I install the new polyurethane subframe bushings anyway, so that can fill the small blemish.

There was no damage to any of the suspension links and they were much easier to remove.

elgin.owens thanks for the pictures of your air hammer set up, helped give me an idea of how to tackle it.

I may replace the front control arm's rear bushings. When they were replaced about 30k ago, the shop that did them, did not orient them correctly.

UPDATE!!

I went to push in the new poly subframe bushings and they fit...but only from the bottom. That is because the OE bushing races were nice enough to rust and leave behind a layer of metal chemically bonded to the subframe.

Time for a home depot run and a bunch of grinding stone bits for my dremel to clearance out the hole...Happy New Year