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Thanks for that awesome tip! I just snagged 2 NOS sets of GM fasteners for a whopping $1.50 total on eBay. I've had those covers off so many times in the past I look forward to installing these.
Can you let me know where on ebay did you get does. TIA
Thanks for that awesome tip! I just snagged 2 NOS sets of GM fasteners for a whopping $1.50 total on eBay. I've had those covers off so many times in the past I look forward to installing these.
When I searched eBay there was only one listing for 2 bags of NOS GM fasteners with that part # for $1.50 and free shipping. I got lucky with that one.
Thanks for that awesome tip! I just snagged 2 NOS sets of GM fasteners for a whopping $1.50 total on eBay. I've had those covers off so many times in the past I look forward to installing these.
sorry, not putting two and two together here - what fasteners? the VC studs? what part number?
any chance you could provide a picture of the studs with some sort of scale for reference? when I bought my 85, it had studs, and I thought they were pre-TSB. I could not use them with gaskets because of the gasket thickness (approx. .140") - the studs were not long enough with gaskets for proper thread engagement of the nuts. when I retrofitted the car with fel-pro 1628" (.250") I went with longer studs. it now looks like, according to Randy M, that pre-TSB fasteners were bolts and NOT studs after all.
back up even farther - when I bought my 85 (november 1995), it had 33K miles on the clock. it also had leaking valve covers. the valve covers did not have gaskets, but RTV sealant, that was not properly applied - looked like the guy was trying to caulk his basement windows. it was a mess. anyway, I assumed that since it had RTV, and studs (that seemed to be too short), and according to the FSM, have RTV sealant, thus pre-TSB. BTW, my VIN-sequence number is late-85, AFTER the TSB production change date. this always confused me. I repaired the leak using RTV and did not have an issue after that. I did not know about the TSB for some 10 years, and only recently started using gaskets, however I had to go with longer studs to compensate for the gasket thickness. I may not be OE, but the VC's are bone dry, and everything seems to be configured correctly.
I too used the thicker FelPro gaskets. I just made my own studs out of some threaded rod I had laying around. And yeah, had to do it twice to compensate for the thicker gasket.
Not off track, this is why we do these threads. Good info guys keep it coming.
any chance you could provide a picture of the studs with some sort of scale for reference? when I bought my 85, it had studs, and I thought they were pre-TSB. I could not use them with gaskets because of the gasket thickness (approx. .140") - the studs were not long enough with gaskets for proper thread engagement of the nuts. when I retrofitted the car with fel-pro 1628" (.250") I went with longer studs. it now looks like, according to Randy M, that pre-TSB fasteners were bolts and NOT studs after all.
back up even farther - when I bought my 85 (november 1995), it had 33K miles on the clock. it also had leaking valve covers. the valve covers did not have gaskets, but RTV sealant, that was not properly applied - looked like the guy was trying to caulk his basement windows. it was a mess. anyway, I assumed that since it had RTV, and studs (that seemed to be too short), and according to the FSM, have RTV sealant, thus pre-TSB. BTW, my VIN-sequence number is late-85, AFTER the TSB production change date. this always confused me. I repaired the leak using RTV and did not have an issue after that. I did not know about the TSB for some 10 years, and only recently started using gaskets, however I had to go with longer studs to compensate for the gasket thickness. I may not be OE, but the VC's are bone dry, and everything seems to be configured correctly.
sorry if we're getting off track....
I'll snap a picture when they're delivered. This thread is awesome, I never knew GM changed to studs.
I'll snap a picture when they're delivered. This thread is awesome, I never knew GM changed to studs.
- I can't believe you got those things for $1.50 shipped. after the seller paid the fleabay and paypal fees, and paid shipping, he probably lost money! I've got some really good buys on fleabay, but nothing like this -- again good find!
really interested in a scaled pic of those studs. that would answer the question as to what I had on my 85 - if it truly was post-TSB, I'm curious about the length. just seemed too short for gaskets. if we had a sample of the gaskets called out in the TSB, and got the thickness dimension, that might shed some light on the issue. i'm thinking forum member "ihatebarkingdogs" might have a set -
I love trying to figure out these little details, especially on the 85 model year.
edit: Randy M - could you post a scaled pic of the OE bolts (and any washers) used to attach the pre-TSB valve covers? curious about the length. also, any original 84's out there - chime in on the valve cover hardware. my understanding is the L83's also used RTV as a valve cover sealant, therefore, it should have bolts. is so, is there a TSB out there addressing a bolt/stud retrofit, or did they just use bolts with gaskets?
- I can't believe you got those things for $1.50 shipped. after the seller paid the fleabay and paypal fees, and paid shipping, he probably lost money! I've got some really good buys on fleabay, but nothing like this -- again good find!
really interested in a scaled pic of those studs. that would answer the question as to what I had on my 85 - if it truly was post-TSB, I'm curious about the length. just seemed too short for gaskets. if we had a sample of the gaskets called out in the TSB, and got the thickness dimension, that might shed some light on the issue. i'm thinking forum member "ihatebarkingdogs" might have a set -
I love trying to figure out these little details, especially on the 85 model year.
edit: Randy M - could you post a scaled pic of the OE bolts (and any washers) used to attach the pre-TSB valve covers? curious about the length. also, any original 84's out there - chime in on the valve cover hardware. my understanding is the L83's also used RTV as a valve cover sealant, therefore, it should have bolts. is so, is there a TSB out there addressing a bolt/stud retrofit, or did they just use bolts with gaskets?
Well Joe, I am not going to promise anything on this one. I am not sure I'll be able to locate them any more. I'll have a look see to what I can come up with. Wish me luck.
In case you guys are interested and may have missed it, I did rebuild the brakes and had a little challenge on the right rear. Here is what happened and how I fixed it.
I also had a couple of surprises when doing the differential seal that led me down a path of no return. I thought the seal would be the least of my problems. Here is the first thing that I encountered. Anyone see anything like this before? The seal was replaced once by a dealership years ago. I assume this the crush spacer that they put in and why the current seal was leaking. The part is plastic and is being extruded into the pinion spline.
Well, as luck would have it, I had on heck of a time getting the flange of the exhaust pipes off of the manifolds. It seems all the studs were bent and me being me decided to replace them with new. I started to do this with the manifolds still in the car. And no good deed goes unpunished and I broke one clean off. There is no way I am going to replace these now in the car and make the fix. So out come the both manifolds and while they're out I did a little rust removal at the same time. Here are some pics of the whole process.
Oh yeah, I decided that I just didn't want to drill a straight hole to remove the broken stud, so I had a little welding and tapping to do. I made a fixture to make sure placement and straightness were all the way it is supposed to be.
GOOD JOB! had a similar issue on my 85 - fortunately, I was able to repair my one problem stud with a helicoil.
as a side note, replace any and all hardware, at least as much as you can, with SS, and "goop" everything with hi-temp anti-seize. at least you'll make it easier for the next guy. try permatex #77134 - nickel based and good for 2400 degrees. BTW, don't replace the exhaust manifold nuts with any type of GM OE stuff. they're plain steel, and the rust like crazy. I used copper (alloy) flanged, locknuts (M10-1.5), BMW p/n 18301737774. you can buy them all day long on fleabay for less than a buck a piece. I have used stainless, and brass alloy, plain nuts in the past, but these are flanged and a (prevailing torque) locking design - works like a champ!
this is probably overkill, but on the last three C4 exhaust systems, I added these washers under the copper lock nuts -
18-8 Stainless Steel Washer - Oversized, 3/8" Screw Size, 0.406" ID, 0.875" OD -- they run .105 to .13 thick -- https://www.mcmaster.com/#98370a030/=19xwjk7
I originally added them to a magnaflow system on my first 90 due to oversized holes in the exhaust pipe flange. not sure if it's a habit now, or what, but the thick washers provide additional support the steel flange. as I said, maybe just overkill -
BTW, wish I knew you were doing this - I have a box of #6 stainless screws that are a direct "form/fit/function" identical to the OE steel screws holding the heat shields in place - could have sent you a hand full. how did you refinish the heat shields? mine were in pretty bad shape, so a trip thru the bead blasting cabinet, and a couple coats of VHT flat aluminum header paint - they look decent. good replacements are damn near impossible to find.
this is probably overkill, but on the last three C4 exhaust systems, I added these washers under the copper lock nuts -
18-8 Stainless Steel Washer - Oversized, 3/8" Screw Size, 0.406" ID, 0.875" OD -- they run .105 to .13 thick -- https://www.mcmaster.com/#98370a030/=19xwjk7
I originally added them to a magnaflow system on my first 90 due to oversized holes in the exhaust pipe flange. not sure if it's a habit now, or what, but the thick washers provide additional support the steel flange. as I said, maybe just overkill -
Yeah, I tend to agree with ya on this one. I don't think they are really needed either. I will evaluate when I go to assemble them. I think I already have some stainless washers in my supply.
Originally Posted by Joe C
BTW, wish I knew you were doing this - I have a box of #6 stainless screws that are a direct "form/fit/function" identical to the OE steel screws holding the heat shields in place - could have sent you a hand full. how did you refinish the heat shields? mine were in pretty bad shape, so a trip thru the bead blasting cabinet, and a couple coats of VHT flat aluminum header paint - they look decent. good replacements are damn near impossible to find.
Well I pretty much decided that I wasn't going for the show car look on this. Just a good clean, repair, and maintenance exercise. So all I did was dunk everything in EvapoRust and call it a day. I may regret not stripping and painting them, but hey such as life. Thanks for the offer though.
