I'm about to add the 1Le brackets to my 9-bolt. Most of the pictures I've seen show brackets without dust shields. Mine have the dust shield. Is there any particular advantage or otherwise to keeping them on or removing them from the brackets?

 

I've 'read' that the shields are held in place with two tack welds, which can break and cause rattling issues.

Never had the shields on my car. No issues.

JamesC

 

True on the tack welds. They seem solid so I'll leave them for now. Thanks.

 

GM dropped the dust shields early 1989 ... there were issues with it and a retro fit kit where avalible to get rid of the dust shields ...

 

Know what the issues were? I could see debris getting stuck between the shield and disk because there's not much separation.

 

Have to look it up again but I do have the GM docs for it so can post that later.

 

Brake moan ... see http://www.turbotransam.com/JanLarsson/89-5-10.pdf .... hopefully you can access that one.

 

I was able to read the doc. Mentions moan but doesn't tie it to the shields. I've got 10 bolt brackets without the shields but both sets of 9-bolt brackets have them. I may just flip a coin. Thanks.

 

Your call, of course. That said, I'd venture to guess that most PBR systems lack the shield. The 1LE fronts, because of spindle modification, weren't equipped with shields either.

JamesC

 

I may take them off just for looks.

 

I took mine off because they were rusted ugly looking things. No difference otherwise and it cleaned it up under their. Then again i spent about 95 bucks getting the whole rear housing and brake mounting plates sandblasted. Looks 1,000,000,000 times better than it did before now that its all painted and cleaned.

 

Mine are totally rust free and still got that golden color. This is California of course. We have other crap but not rust.

 

This is for the PBR 9 bolt ... first version had the dust shields and the later version didn't and the document addresses the change for the moan was to remove the dust shields / bracket and replace with just the bracket used on the later version (early 89) 9EQ rears.

 

Early 89 got the 9EQ rear without the dust shield as they had issues with them ... so better without :-)

 

The brake moan wasn't due to the shields it was because the that bracket was to small,thin and lacked renforcement. If you look at the later replacement bracket that was after these, it is thicker and has an bend on the edges.
I have 2 89 formula 350s in my garage, one has the shield and the other doesn't.
my 89 ttop car with vin 241249 had the bracket with shields. 03/89
my 89 asc vert with vin 251614 has the bracket without the shields. Couldn't see the date on door tag.
soooo sometime within these VINs the bracket was updated to the thicker stronger one without the shield.

These are off of a 89 TTA. I may be able to go see the vin as the car is looow miles and was pulled apart years ago to go racing and it never made it back.. sad. I'm going to try and buy it..

 

As always very good info.

I never seen the dustshield version up close only on pictures I have so hard to tell the difference between the bracket design but that all make sense then.

Only thing I've seen so far is that the earlier version of the rear end with the dushields on them (on 1989 TTA's) the code on the diffcover is 8EU and not 9EQ ... maybe the swapped the labels out as well when they swapped the brackets @ the dealership?

Thanks for educating us

 

Jan, maybe I'm just getting old and forgetful !!
I had 5 of these rearends back in the day and I would have bet money all the tags were the same, maaybe not!! (kinda like the battery stickers.. ugh) lol
soooo now I need both of these rearend paper stickers made !!!!

 

Could be age :-)

When I got the service bulletin (or acutally looked at it and the VIN break point) I looked at all photos I have of around 300 TTA's to see if I could identify which rearend they had (early or late) and a couple still had the stickers on the diff cover on them and they did say 8EU on there (so the early style bracket with dustshield) and all I had without that setup after the VIN break point say 9EQ ...

Both 8EU and 9EQ is listed with the same details also for the 89 model year when I looked it up some time ago hence my conclusion on that one.

Might get around making those stickers one of these days ... I'm sure there's interest out there for 3 or 4 in total lol.

 

I think John Zofko "Okfoz" has the 9EQ made for his 89 formula 350 vert. He sent me a copy. I'll have you ask him for that info if you want it so I'm not stepping on toes!

 

I got the 9EQ, had it made years ago, as this is factory correct for mine but done have the 8EU sticker ... got photos but not sure they are good enough to figure out the barcode on there, never spent any time on it as mine did come from the factory with the 9EQ sticker.