C3 LS4 Upper control arm removal

[Mark E.]

Re: C3 LS4 Upper control arm removal

Tom,

Just saw your thread. As Dom stated, the shroud is removed by removing the upper and loosening the lower core support bolts so the support can be tilted forward. This is the recommended method detailed in the CSM. I read on this Forum some folks remove the A-arms instead, but I've never tried it. If you have AC, you may need to also remove the condensor or the headlight cans so the core support can be tilted forward enough to enable removing the shroud.

If the upper A-arm pivot bolts are tight like they should be, don't mess with them. One of mine spun loose so I had to weld it to the frame (as Joe mentioned).

Looks like you're making good progress. Bummer about the broken shroud but keep going.

[Tom K.]

Re: C3 LS4 Upper control arm removal

Hi again Mark - saw you on my other thread - What process would you recommend for putting this beast back together again?
Assemble the Core Support, Condenser and Radiator together then install the unit at the same time as the fan shroud?

Again, thanks to all for the advice


Tom

[Patrick H.]

Re: C3 LS4 Upper control arm removal

Hi Patrick,

I got the thing apart the rest of the way and I was pleasantly surprised that the rust was not real bad. I expected to have to at least weld in a panel and finish the thing for a repair, but it is pretty solid and should clean up just fine. A wire wheel and maybe the sandblaster in some areas and I will just paint it up. Also wondering of there is a smart-guy way to remove those plastic fasteners that hold on the foam seals without breaking the fasteners? Thanks again everyone for the advice!

They will usually just pull out, but they should be metal.
Doc Rebuild sells new push-in fasteners as well as new foam seals.

[Tom K.]

Re: C3 LS4 Upper control arm removal

Hey Patrick - Hey Joe,

Guess what? After I got the crud off my radiator support that I thought was in pretty good shape - i found its not as solid a s it looked. Lots of pinholes (or bigger) in the lower part of the support. I will also need to weld on new lower support brackets, because beneath the rubber isolators, they were really rusted.
Couple questions again -
First
Does anyone make lower radiator mount brackets that have the fan shroud bracket already welded on? The ones I have found at most every Corvette parts supplier are just the U shaped stamping, the flat bracket and stud are not there.
Second
I have an opportunity to get for a really good price a radiator support for a 73 Corvette that was originally in a small block car. I dont think they are the same - are they?

Thanks yet again for all your advice


Tom

[Russ S.]

Re: C3 LS4 Upper control arm removal

73 BB and SB radiator supports are the same. The radiators are the same also. Edit: see post 22 below for clarification.

Hey Patrick - Hey Joe,

Guess what? After I got the crud off my radiator support that I thought was in pretty good shape - i found its not as solid a s it looked. Lots of pinholes (or bigger) in the lower part of the support. I will also need to weld on new lower support brackets, because beneath the rubber isolators, they were really rusted.
Couple questions again -
First
Does anyone make lower radiator mount brackets that have the fan shroud bracket already welded on? The ones I have found at most every Corvette parts supplier are just the U shaped stamping, the flat bracket and stud are not there.
Second
I have an opportunity to get for a really good price a radiator support for a 73 Corvette that was originally in a small block car. I dont think they are the same - are they?

Thanks yet again for all your advice


Tom

[Tom K.]

Re: C3 LS4 Upper control arm removal

Russ,

So any differences are in the brackets?

Tom

[Russ S.]

Re: C3 LS4 Upper control arm removal

What brackets are you referring to? The only difference that I am aware of in the radiator surround is that the early 73 didn't have the four holes (two on each side) on the top of the support for the two brackets that mount to the fan shroud. Later 73 and 74 had these four holes on all supports but only the BB had the two brackets.

[Tom K.]

Re: C3 LS4 Upper control arm removal

I was thinking that the SB and BB radiators were different widths between tanks and the support brackets were different to make up the difference. But I realize now that the lower ones are welded in place, so that cant be the case. Thanks for your help Russ.

[Mark E.]

Re: C3 LS4 Upper control arm removal

If you need another source for a core support, I recommend Coffman Corvette. They manufacture them in the Midwest and supply many of the parts houses. They also sell direct. The one I have from them fit and looks perfect. They may have advice about the radiator brackets you need.

Installation sequence as I remember it:
- all belt driven components except alternator and fan
- core support (bottom 2 bolts only so it can be tilted forward)
- lay shroud across water pump
- slide in radiator while tilting core support and wiggling shroud as needed
- bolt up core support, shroud and related seals but don't tighten shroud yet
- belts, fan, alternator
- adjust shroud so there's 1 finger of clearance as you rotate fan
- hood

CSM may have this also.
-

[Tom P.]

Re: C3 LS4 Upper control arm removal

My son and I recently built a healthy SB400 to replace the tired L48 in his 73 with factory air and auto.

THE GUY THAT DESIGNED THE INSTALLATION OF THAT FAN SHROUD SHOULD BE TARRED AND FEATHERED AND RUN OUT OF THE USA!!!!!!!!!!! OR MAYBE JUST SHOOT HIM!!!!!!!!!!

[Russ S.]

Re: C3 LS4 Upper control arm removal

I am adding an edit as I misspoke as to only BB having the two brackets. In 74 for sure the two radiator support to fan shroud brackets were used on SB as well. At this point I don't think any 73s used the double bracket. Can others chime in here.

What brackets are you referring to? The only difference that I am aware of in the radiator surround is that the early 73 didn't have the four holes (two on each side) on the top of the support for the two brackets that mount to the fan shroud. Later 73 and 74 had these four holes on all supports but only the BB had the two brackets.

[Tom K.]

Re: C3 LS4 Upper control arm removal

Hello Russ,

Quite a few things have happened since my last post - radiator is back - condenser cleaned up and fins straightened - got new hoses belts etc - still need the fan shroud and I found a bracket in a Corvette parts supplier catalog that wasnt on my car. The bracket is listed as GM part # 339178 and named Fan shroud bracket, upper RH. I cannot find this in my CSM, or the AIM - I have checked the 11E section for the core support and the 13E section for the fan shroud with no luck. Is this the bracket you were referring to in your post above (Feb 23rd at 10:25)?

Thanks in advance for any advice


Tom Krause

Quick edit -- I should have also asked where the p/n 339178 bracket goes. As it wasnt on my car and I cant find it in the AIM, I have no ides.

Thx

TK

[Russ S.]

Re: C3 LS4 Upper control arm removal

Yes, That is the RH bracket of the two I was referring to. Your car being a 73 didn't use these two brackets. It only uses the center top bracket that goes from the radiator support to the fan shroud.

Hello Russ,

Quite a few things have happened since my last post - radiator is back - condenser cleaned up and fins straightened - got new hoses belts etc - still need the fan shroud and I found a bracket in a Corvette parts supplier catalog that wasnt on my car. The bracket is listed as GM part # 339178 and named Fan shroud bracket, upper RH. I cannot find this in my CSM, or the AIM - I have checked the 11E section for the core support and the 13E section for the fan shroud with no luck. Is this the bracket you were referring to in your post above (Feb 23rd at 10:25)?

Thanks in advance for any advice


Tom Krause

Quick edit -- I should have also asked where the p/n 339178 bracket goes. As it wasnt on my car and I cant find it in the AIM, I have no ides.

Thx

TK