FYI ZF rebuild info......... - ZR-1 Net Registry Forums

WydGlydJim · 02-19-2008

Just thought I'd let everyone know that there can be some interchangeability issues with the '90 ZF when going with different rebuild options. My personal choice was to use a non ZR-1 ZF, and swap the guts into my original case, and change the input shaft. I feel this is the least expensive option, with very good results. However, here is the catch, the '90 has a unique bolt pattern for the exhaust hanger, that is changed in the later tailshafts. If you do not use the original tailshaft, the exhaust hanger will not bolt up properly! Does it cause a problem? No, but it just isn't right. This slipped past even the expertise of Bill B. so I wanted to get the word out. He thought he was doing me a favor by using the new tailshaft, with the new seal and what not. I now have to either change my tailshaft; (the install is complete; that's like one of the very last things you hook up) or live with it. I want to make clear, this is not a BB bashing thread, but more of a learnig curve/informational thread for all of us involved with these great machines.

-=Jeff=- · 02-19-2008

Why not get a later exhaust hanger from a LT1/4 car? it should work and saves from changing out the tailshaft on the trans

WydGlydJim · 02-19-2008

Quote:

Originally Posted by -=Jeff=-

Why not get a later exhaust hanger from a LT1/4 car? it should work and saves from changing out the tailshaft on the trans.

Yes, that is a good option from a practical and engineering standpoint, but it doesn't address the components looking right.

bradslt5 · 02-19-2008

thanx for the info. but to me , to have the new tailshaft and switching to the lt4 hangers is the way i would go . but i am just a drag racer thats not into keeping her factory perfect . having headers and after market exhaust negates the need to be factory perfect. jmho

GOLDCYLON · 02-19-2008

Quote:

Originally Posted by WydGlydJim

Yes, that is a good option from a practical and engineering standpoint, but it doesn't address the components looking right.

Honestly unless your car is a NCRS ride how the heck is anyone going to be able to tell the difference? "only your hairdresser will know"

WydGlydJim · 02-19-2008

Quote:

Originally Posted by GOLDCYLON

Honestly unless your car is a NCRS ride how the heck is anyone going to be able to tell the difference? "only your hairdresser will know"

I hear ya.......just getting the info out there for everyone.......I just would have rather it not have happened at all, and don't want it to happen to someone else.......I requested stock casing all the way around, not just the numbers matching part......just kind of aggravating......plus, I have not seen hide nor hair of my original tailshaft!

GOLDCYLON · 02-19-2008

Quote:

Originally Posted by WydGlydJim

I hear ya.......just getting the info out there for everyone.......I just would have rather it not have happened at all, and don't want it to happen to someone else.......I requested stock casing all the way around, not just the numbers matching part......just kind of aggravating......plus, I have not seen hide nor hair of my original tailshaft!

Got it I understand.

cuisinartvette · 02-20-2008

So he kept the old parts is what youre saying? Those sell for good $ I hear.

WydGlydJim · 02-20-2008

Quote:

Originally Posted by cuisinartvette

So he kept the old parts is what youre saying? Those sell for good $ I hear.

Some parts were returned, and I let Bill keep some. The tailshaft was not part of the original agreement. It would be a good idea to make sure the parties are very clear on the return of parts before work is started. Just a heads up.

02-19-2008	#1
WydGlydJim Join Date: Jan 2008 Location: Wichita, Ks. Posts: 319	FYI ZF rebuild info......... Just thought I'd let everyone know that there can be some interchangeability issues with the '90 ZF when going with different rebuild options. My personal choice was to use a non ZR-1 ZF, and swap the guts into my original case, and change the input shaft. I feel this is the least expensive option, with very good results. However, here is the catch, the '90 has a unique bolt pattern for the exhaust hanger, that is changed in the later tailshafts. If you do not use the original tailshaft, the exhaust hanger will *not bolt up properly!* Does it cause a problem? No, but it just isn't right. This slipped past even the expertise of Bill B. so I wanted to get the word out. He thought he was doing me a favor by using the new tailshaft, with the new seal and what not. I now have to either change my tailshaft; (the install is complete; that's like one of the very last things you hook up) or live with it. I want to make clear, this is not a BB bashing thread, but more of a learnig curve/informational thread for all of us involved with these great machines. __________________ 2009 LS9 1990 LT-5/sold/Bought my Baby back 1994 Lingenfelter LT-5/sold 1973 LS4/sold

02-19-2008	#2
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,169	Re: FYI ZF rebuild info......... Why not get a later exhaust hanger from a LT1/4 car? it should work and saves from changing out the tailshaft on the trans __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

02-19-2008	#4
bradslt5 Join Date: Oct 2007 Location: lone pine and mammoth lakes ca. Posts: 544	Re: FYI ZF rebuild info......... thanx for the info. but to me , to have the new tailshaft and switching to the lt4 hangers is the way i would go . but i am just a drag racer thats not into keeping her factory perfect . having headers and after market exhaust negates the need to be factory perfect. jmho

02-20-2008	#8
cuisinartvette Join Date: Aug 2005 Location: San Fernando Valley, CA. Posts: 896	Re: FYI ZF rebuild info......... So he kept the old parts is what youre saying? Those sell for good $ I hear. __________________ 1990 ZR1, 142,000 miles-Black on black 4.09's Haibeck chip, 3"exh, K&N, meth inj.