Suspension Bushing Replacement.

[sqbsprite]

My main project this winter will be to replace all the suspension bushings on my '71 TR6. Today I made all the preliminary measurements of camber, toe-in and ride height. I plan on using the adjustable rear trailing arm mounts. I have noted the number of shims under each mount. See if you can spot the problems on just one of my mounts in the photo.

IMG_20141129_160825_771.jpg

[smaceng]

looks like the bracket is cracked at the lower mounting bolt$CIMG2265a.JPG
Scott in CA

Can you see what I found in my rear suspension?
CIMG2272a.JPG

[sqbsprite]

Scott, Well, that's not supposed to be there. Looks like it did some damage.

[tdskip]

Give a strong consideration to using poly bushings, in my experience the rubber ones don't last.

[Scot1966]

My main project this winter will be to replace all the suspension bushings on my '71 TR6......I plan on using the adjustable rear trailing arm mounts.

My bushings looked like yours do. I did mine 2 weeks ago. I used a 3/16" drill bit to put as many holes through the bushings as possible, ( favor the bolt bushing so you don't hit the trailing arm itself ) and the bushings push out easily. A small flap wheel on a dremel will clean out what's left in the socket.
I also used adjustable brackets, and after being on the fence a while, went with Prothane bushings.

[sqbsprite]

I will be using polyurethane bushings. Thanks for the tip. I'll use the drill method if they are stubborn. The toe out is 1/8". There are 5 shims under the RH outer bracket. I am thinking someone tried aligning it with the bad bushings. I wonder if I should start out with only 2-3 shims to see if it is closer once I get the new brackets in place. Of course the camber was really bad due to the worn out bushings. I've been reading some posts about the whole process. I've done fronts on other LBCs, but this is my first try on a TR.

[tdskip]

Hi Steve, I think you will find it all be straight forward. The shims are easy to do afterwards so maybe finish the rebushing then decide how many shims. That said I think I remember using two a side as a starting point...

Keep us posted, and remember we love pictures. Hint, hint

[tomshobby]

I found that an old clutch release bearing sleeve works well for pushing the old trailing arm bushings out.

[sqbsprite]

I'll be posting pics once I get started. I just ordered the brackets from Good Parts. I had bought everything else during various sales. I like to have everything on hand and be studied up before I do something the first time. Regarding the adjustments on the brackets. Is a good starting point in the middle? Or would it be best to set the outer one up a couple of turns? I am assuming it's best to turn the adjustments with the weight off them. Then set the car down and roll and bounce it a bit. Any tips here will be appreciated.

IMG_20141129_161237_910.jpg

[sqbsprite]

Yesterday, I started with the RH rear trailing arm. Dis-assembly was easy. I had to remove the brackets with the trailing arm because there is no frame clearance to get the pivot bolt out. The removal of the rubber bushings were a major pain. The OEM style bushing is one piece with a lip on both sides. I cut the lip off and then I used the drill to make about twelve 3/16" holes all around the bushing close to the metal sleeve. After that, it was still a pain to pry out. I found that using one of the pivot bolts as a drift helps push the bushing out. After all that work, I found a crack in the trailing arm. So I have two questions.
1. What is the best and easiest method to get the bushings out?
2. I'm not finding much in regards to the cracked arm. I am thinking about having it TIG welded. Anybody had this problem? See photo.

[IMG][/IM[IMG][/IMG]G][IMG][/I[IMG][/IMG]MG][IMG][/IMG][IMG][/IMG][IMG[/IMG

[Gliderman8]

I used a threaded rod with some flat washers and some sockets to pull the bushing out.

[Scot1966]

With that many holes, I am surprised you had trouble getting them out. Mine came out fairly easily with that method. The bolt used as a drift is a good idea. As for the crack....I would TIG weld it.

[tdskip]

I used a threaded rod with some flat washers and some sockets to pull the bushing out.

+1

[TR3driver]

1. What is the best and easiest method to get the bushings out?

Not sure if it meets those qualifications, but when rubber bushings like that are stubborn, I just heat them up with a propane torch. Usually the rubber will melt before it burns, and you can push it out with a punch or stick (being careful not to get the melted rubber on your skin). You'll still have to clean the hole up afterwards of course, but that will get most of it out.

[Tybalt]

Yesterday, .....
2. I'm not finding much in regards to the cracked arm. I am thinking about having it TIG welded. Anybody had this problem? See photo.

[/IMG][IMG

Gas Tunsten Arc Welding (GTAW) is the term used by the American Welding Society for what is commonly called TIG welding. GTAW would be the appropriate technique for affecting a repair of this crack. They will likely need to do a bit of gouging as part of the preparation for welding. Were I to be doing this work, I would use a 4043 filler and give it a post weld age thermal treatment at ~325 to 350° F for 8 to 10 hours. This won't get it back to 100 percent of the fully solution and precipitation heat treated strength at the weld, but it should be you about 80% of the way there at the weld area. You will need to be gentle with it when it is hot as there is large property knockdown at temperature. There would be a very slight residual knockdown of properties for the rest of the part following this aging treatment once it gets to room temperature, something typically on the order of about 3% or so.

[sqbsprite]

Thanks for everyone's input from last week. So today I removed the LH side and I think I found a decent method for removing the bushings. At least these two came out much easier. I still cut the flange off on side to make it easier to push out. I then used a large 3/4 drive 1-5/8" socket to pull against with a 6" C clamp. I used the pivot bolt to give the clamp something to push against. This arm has no cracks. Looking at the rear differential mounts I see one bushing has a split in it. The PO had just had the diff mounts repaired and it looks like a good job. I will go ahead and replace the bushings with poly ones. I think the bad trailing arm bushing contributed to some stress on the diff bushings. Now for my questions.
1. Were the arms painted black from the factory or left bare aluminum?
2. I see some oil leaks around the diff. axle flanges. I'm think I should replace the seals and gaskets once I remove the diff. Any difficulties I should know about the axle flange seals? I see red silicone, so I know someone has been into it before.
[IMG][/IMG]
You might want to use a better C clamp. This one was bent from a previous job.
[IMG][/IMG]
It worked pretty well.
[IMG][/IMG]
You can see here how off center the bushing was.

[pdplot]

I'm beginning to think that my thumping rear end noise may be due to a worn bushing. I replaced the right rear with new rubber last year when I replaced the suspension arm. But - we left the left side alone. Now, it looks tired and I'm thinking of replacing the rubber with Richard Good's nylatron bushings.
1. is this a good idea? How are these bushings?
2. Does it matter that the right side still has new rubber bushings?
Thanks for any input.

[sqbsprite]

I'm beginning to think that my thumping rear end noise may be due to a worn bushing. I replaced the right rear with new rubber last year when I replaced the suspension arm. But - we left the left side alone. Now, it looks tired and I'm thinking of replacing the rubber with Richard Good's nylatron bushings.
1. is this a good idea? How are these bushings?
2. Does it matter that the right side still has new rubber bushings?
Thanks for any input.

It would not be a good idea to have bushings of different material on each side. It would affect your handling and possibly in an unpredictable way. Nylatron is a very hard material. I used them in my MGB front A arms and I decided I would not use them again on a street car. They were stiff which was good, but they transmitted a lot of road vibration. That said, I think they would definitely last a long time.

You might want to check your differential mounts for the thumping noise. When they go bad, they allow the differential to move and cause a thump. Also, when they are bad, it increases the risk of the mounting frame getting damaged. You definitely want to make sure it is solid if you are replacing the bushings because the diff would have to come out again to repair it.

[Tybalt]

It's like sqbsprite says, different durometer bushings side to side is not a good idea and the Nylatron bushings are extremely hard. I have fitted the Nylatron bushings from Richard and they did require a bit of fiddling with to insure a good fit. They were on the large side to accommodate casting tolerances and had to be sanded to fit. Not a bad job, but a bit tedious all the same.

I also concur with his assessment that you need to check the diff mounts. There are two kinds of IRS running TR4A/250/5/6 out there. The ones that have had the diff mounts repaired and reinforced and those that need it done. Definitely have that checked out.

If you are thinking of buying some of the rear suspension bits from Richard, the thing that should be at the top of your list are the adjustable trailing arm brackets (your alignment guy will want to hug you for having them as they make rear camber adjustment much easier), just be prepared to replace some of the supplied hardware supplied with them. The frame to bracket mount bolts were too short when I did mine for using the toe adjustment shims and the pivot bolts for the trailing bushings had an extended threaded section that allowed threads in shear loading (as an engineer I hate having threads in shear loading). I would up using some AN hardware from Aircraft Spruce for the pivot bolts. If I'm recalling correctly they were AN7-41A which a 7/16"-20 bolt, nominal overall length of 4 7/32" with a 3 9/16" grip length, undrilled shank and head. Being the somewhat anal retentive type, I also applied some Dow Corning molybdenum disulfide solid film lubricant to the grip area of the bolts.

[pdplot]

Thanks for your input. Invaluable. I will probably stick with the rubber. Question - what's the best way to check the differential mounts?