Tomorrow's the day...engine and rear end/disc brake swap at the

same time. I have already searched and read all related posts.

Now, before I tear into this, I just want to make sure I have all

bases covered. The car is a 92 Trans Am / LB9 305 TPI / 700r4 /

10 bolt posi drum / 2.73 gear. My donor car is an 87 IROC / Fresh

rebuild LB9 / 700r4 / 9 bolt posi disc / 3.23 gear.

As far as the rear swap goes...yank the old...slip in the

new...change the driven speedo gear from 37 tooth red to 44 tooth

dk. gray...swap the e-brake cables all the way to the lever since

the 92 does not have the adjusting mechanism...then bleed em.

Master cylinder and propo valve in the 92 should work fine...Did

I miss anything?? Any tips on the e-brake??

The engine swap is straight forward...just swapping the long

block. The one in the TA was seized up when I bought it...the

IROC had an overhaul less than 10k miles ago. I'm gonna pull the

engine/tranny together since the seized engine won't turn at all

to allow me to get to the flexplate to convertor bolts...swap

trannies out of the car and drop it back in.

I have recruited the help of a mechanic buddy and my 14 year old

son (who is always tons of help and is learning alot about cars)

and I have access to a shop with a lift and air. Our target is 8

hours start to finish. Hopefully we can get it done in twice

that...hehe.

Any last minute suggestions?? I'll let you know what happens.

Thanks in advance
TurbineJock

turbinejock@yahoo.com




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There is no substitution for cubic inches!

 

Keep a journal for us! That seems like one hell of a swap day.. I'd love to be in on it.

Yes, the m/c will be fine. Apeiron dug up an old GM bulletin saying that your current J50 master cylinder (the old '84-'88 "disc/drum" one) could be installed on a 4-wheel-disc car if the customer complained of the brake pedal being too firm. Apparently the only deal with the J65 (4-wheel-disc) master cylinder is improved pedal "feel", caused mainly by the larger bore (25.4mm = 1 inch, as opposed to the J50 24mm bore).

As to the prop valve; I thought they were different. You'd probably be fine for driving, since your front brakes will act as they always did, but you might not get all the braking power possible from the new rear discs. Does anyone know?

Oops- I just noticed you're talking about a 9-bolt rear and not my familar 10-bolt. Do those have different rear calipers?


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-Tom P (Hot rodded 1986 Firebird 2.8l)

 

9 bolts and 10 bolts have the same rear disc setup I think, just different backing plates.

 

Thanks guys...This board is awesome for us 3rd genners...I'll swap the propo valve too...what about the brake lines?...a reply in the other forum suggests that they have different fittings...I'm planning to use the ones from the IROC as they are less than a year old...does anyone know if they will fit the fittings on the 92?

TIA

 

UPDATE... Well...we fell a little short on time...but still got alot done. We had a ton of trouble getting the rear end out of the 92 TA due to rusted bolts...ended up cutting some with a torch as this car has been sitting in a salvage yard for 6 years. We finished the rear/brake swaps and got both engine/tranny's out. Looked up and it was 5 and we had to get out of the shop. Now all I have left to do is re-gasket the engine for the TA and drop it in. I'm still satisfied with the progress since we had so much trouble in the beginning. We'll finish next weekend.

Thanks alot for the help and advice.

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There is no substitution for cubic inches!

 

Blown_n_Injected-

If you need any help, I would be glad to help out for the learning experience alone. I am considering doing an engine swap on my 92' and would love to see/help with one in progress. I am out in Sugarland, and would enjoy meeting up with you if you need any help.

Alex

 

I hope you are intending to swap in the entire e-brake pull-up handle assy. As you correctly stated the 89-92 doesn't have the center threaded adjustment rod that you will need for the 87 rear disc brakes. You just won't get enough pull-up on the e-brake cables if you don't make the swap of the e-brake handle assy as well. I know from experience. I even tried some spacers on the cable to get it to tighten enough. I finally broke down and bought the correct one at a Pick-a-Part. Good luck with the swap.

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90 RS Convertible
Owner: Top-Down Solutions

http://www.sc3gfb.org/members/lonsal.html
http://www.taskerinc.com/gs3/profiles/Lon_profile.htm

 

The 89-90 cars should have the threaded rod, only the 91-92 cars are self-adjusting.

 

Thanks Red for the offer, at this time we are actually almost finished. We had slipped this project in my buddies shop as his own so the owner of the shop would let him work on their day off. When you are ready to do your swap, let me know, I'll offer any help I can should you need any assistance. As for the brakes...got the whole lever assembly! The only thing I regret is that I didn't get to document the swap with photos. I had my digital camera there but was so busy I didn't even break it out. Should have brought a photographer!

Thanks guys, You have been alot of help.

 

My 90 didn't have the threaded adjusting rod, my 88 Iroc does. I was basing it on the year the brakes changed. So it looks as if 89 was the last year for the threaded adjusting rod.

 

Interesting, not according to the assembly manual.

 

Your right. The 1980-1991 Parts & Iillusrtration Catalog #17F I have shows that the '82-'90 parking brake has the threaded adjusting rod (pg 4-100). On the next page it shows the '91 as having the non-adjustable type. I guess I wasted my time by replacing mine. Since according to the book it should have had the adjusting rod type already. Mine is a 'vert, but I shouldn't think that would make a difference. The '91 illustration also shows the disc brakes as being the leading/trailing caliper setup, which is also wrong. Books sometimes have mistakes.

[This message has been edited by lonsal (edited August 23, 2001).]