Rear diff swap DIY advised?
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From: Foresthill CA
Rear diff swap DIY advised?
Thanks to Mike Mercury for the inspiration and Mark Norris for the Corvette Fever article detailing the carrier swap.
For those of you contemplating swapping the rearend out yourselves, go for it! I now have an intimacy with the design that I wouldn't have otherwise.
:yesnod: :cheers:
For those of you contemplating swapping the rearend out yourselves, go for it! I now have an intimacy with the design that I wouldn't have otherwise.
:yesnod: :cheers:
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Re: Rear diff swap DIY advised? (Stu in CA)
damn, that must be ine setup garage you have.....if I had the proper space and tools, I would attempt it as well, I have those articles and a set of manuals.....and Mike is close by ;) :D
congrats :cheers:
congrats :cheers:
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Re: Rear diff swap DIY advised? (Mean Green 2000)
I now have an intimacy with the design that I wouldn't have otherwise.
I now have just under 500 miles since my 3.42 upgrade. Absolutely no error codes nor shifting problems ( I went from the 3.15 to the 3.42 retaining the stock TC and did no PCM reprograming). The WOT 5900-6000rpm A4 shifts are heart pounding excitement.
I got a chance to drive recently in near 60 degree weather and found that I am squealing the tires a little bit from a first to second WOT shift... it never done that before. Standing starts give almost too much tire rotation; borderline burnouts. Plus nailing the throttle @ 30mph (along with the A4 downshift) equates to a pleasing little chirp from the rear tires... another surprise.
I couldn't be happier with this DIY - under $1000 - upgrade. Actually the total cost came in @ $700 since I had someone waiting to buy my 3.15s :)
Glad it worked out well for you. Have you had a chance to determine any improvement?
I don't remember, but did you install an aftermarket TC, or do any PCM shift point reprog?
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From: Foresthill CA
Re: Rear diff swap DIY advised? (Mike Mercury)
Hey, Test Pilot.
I retained the stock converter, we do a lot of stop and go on the way home eastbound H50 through Sacramento and the driveability didn't change under normal throttle off the line. Plus, I wanted to keep the cost down, got the rearend for $550, picked up that Harbor Freight tranny jack, bought a couple bottles of gear oil and that was it.
Did the PCM change with a HPPIII I got used, cheap from the forum. Went 50% on shift firmness, but might decrease that, as the TC activates on WOT 1-2 shift. :D
Yep, after about 1000 miles, no codes, no probs, and going to WOT around 20-30 like you said, results in a loud chirp and TC activation!
Thanks again!
(I promised my gf I would be done after this, but...might go for a cam and pulley install next, after I get the Z bars and links on!) :eek:
I retained the stock converter, we do a lot of stop and go on the way home eastbound H50 through Sacramento and the driveability didn't change under normal throttle off the line. Plus, I wanted to keep the cost down, got the rearend for $550, picked up that Harbor Freight tranny jack, bought a couple bottles of gear oil and that was it.
Did the PCM change with a HPPIII I got used, cheap from the forum. Went 50% on shift firmness, but might decrease that, as the TC activates on WOT 1-2 shift. :D
Yep, after about 1000 miles, no codes, no probs, and going to WOT around 20-30 like you said, results in a loud chirp and TC activation!
Thanks again!
(I promised my gf I would be done after this, but...might go for a cam and pulley install next, after I get the Z bars and links on!) :eek:
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From: Foresthill CA
Re: Rear diff swap DIY advised? (wallstAL)
I'll check the manual, see how intimidating it looks, heh-heh. Any feedback you know of? Sheesh, after the service I got at the dealer for a smog problem, what harm could I do? :mad
Guess I should start a new thread, "Advice re cam/valve train/pulley DIY?"
My helper/buddy has rebuild experience back in his big block days, have to check it out!
Anybody?
Guess I should start a new thread, "Advice re cam/valve train/pulley DIY?"
My helper/buddy has rebuild experience back in his big block days, have to check it out!
Anybody?
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Re: Rear diff swap DIY advised? (alan33)
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From: Hendersomville NC
Re: Rear diff swap DIY advised? (Mike Mercury)
Thanks Mike:
Looks pretty straight forward. I have a 6 speed and will probably not drop the whole tunnel, just slide the diff off of the back while tilted down.
Take Care,
Alan
Looks pretty straight forward. I have a 6 speed and will probably not drop the whole tunnel, just slide the diff off of the back while tilted down.
Take Care,
Alan
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Re: Rear diff swap DIY advised? (Chris@SpeedDemon)
if there was enough clearance behind the carrier; you could change it without taking anything apart. But the shaft coming from the tranny is just about as long as the carried is deep; there simply isn't enough room to slide the carrier off the tranny driveshaft without dropping the transaxle down.
Since the torque tube is firmly bolted to the engine, you really can't just unbolt the back of the suspension and let the assembly hang down. Well... maybe you could if you loosened the engine mounts.
I really thought about it, and then looked hard for an alternate method that what was shown in the service manual. But couldn't come up with a workable work-around. If you figure it out, post it. Many would like an easier method to swap carriers
[Modified by Mike Mercury, 12:01 PM 3/1/2002]
Since the torque tube is firmly bolted to the engine, you really can't just unbolt the back of the suspension and let the assembly hang down. Well... maybe you could if you loosened the engine mounts.
I really thought about it, and then looked hard for an alternate method that what was shown in the service manual. But couldn't come up with a workable work-around. If you figure it out, post it. Many would like an easier method to swap carriers
[Modified by Mike Mercury, 12:01 PM 3/1/2002]
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From: Foresthill CA
Re: Rear diff swap DIY advised? (Mike Mercury)
Thought you'd address that idea of "just sliding it off the back," wouldn't that have been easier!
I'd suggest thoroughly researching that idea of loosening the motor mounts to gain more of an angle, sounds like it would increase the likelihood of damaging the composite firewall/dash for sure. That warning sticker on the torque tube showing the max amount/angle the tube can be dropped in rear before the firewall is damaged is to be taken seriously. I believe there is a warning in the manual as well. I saw a fellow looking for a used one in parts for sale, I think he said he didn't support the rear of the engine when he removed the tube. I think the manual warns about this as well. My .02.
[Modified by Stu in CA, 9:42 AM 3/1/2002]
I'd suggest thoroughly researching that idea of loosening the motor mounts to gain more of an angle, sounds like it would increase the likelihood of damaging the composite firewall/dash for sure. That warning sticker on the torque tube showing the max amount/angle the tube can be dropped in rear before the firewall is damaged is to be taken seriously. I believe there is a warning in the manual as well. I saw a fellow looking for a used one in parts for sale, I think he said he didn't support the rear of the engine when he removed the tube. I think the manual warns about this as well. My .02.
[Modified by Stu in CA, 9:42 AM 3/1/2002]
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Re: Rear diff swap DIY advised? (Stu in CA)
That warning sticker on the torque tube showing the max amount/angle the tube can be dropped in rear before the firewall is damaged is to be taken seriously. I believe there is a warning in the manual as well. I saw a fellow looking for a used one in parts for sale, I think he said he didn't support the rear of the engine when he removed the tube
[Modified by Mike Mercury, 1:18 PM 3/1/2002]
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From: Hendersomville NC
Re: Rear diff swap DIY advised? (Mike Mercury)
Mike:
I made my previous comment after looking at the CF article and before I got to the bottom of your informative website, quite good. From the picture of the rear end dropped down on the transmission jack, I cannot tell whether you took the diff off from the tilted position shown or if that was an interium picture right before you removed the entire tunnel assembly.
My point is that when you get the tunnel dropped down far enough to remove it, you have it far enoungh down to slide the diff off the transmission while clearing the center luggage compartment, so why go to the trouble of removing the whole tunnel if you are not going to do TC or Clutch work. In the picture you show, it is low enough to remove the diff without taking the entire tunnel out.
Thanks,
Alan
I made my previous comment after looking at the CF article and before I got to the bottom of your informative website, quite good. From the picture of the rear end dropped down on the transmission jack, I cannot tell whether you took the diff off from the tilted position shown or if that was an interium picture right before you removed the entire tunnel assembly.
My point is that when you get the tunnel dropped down far enough to remove it, you have it far enoungh down to slide the diff off the transmission while clearing the center luggage compartment, so why go to the trouble of removing the whole tunnel if you are not going to do TC or Clutch work. In the picture you show, it is low enough to remove the diff without taking the entire tunnel out.
Thanks,
Alan
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From: Temple Georgia
Re: Rear diff swap DIY advised? (alan33)
Alan,
From your replies I assume that you are going to do this soon. Which gears are you going to use? Are you going to try it all by yourself? Last, where did you get your assembly.
From your replies I assume that you are going to do this soon. Which gears are you going to use? Are you going to try it all by yourself? Last, where did you get your assembly.
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Re: Rear diff swap DIY advised? (c5 Lee)
My point is that when you get the tunnel dropped down far enough to remove it, you have it far enoungh down to slide the diff off the transmission while clearing the center luggage compartment, so why go to the trouble of removing the whole tunnel if you are not going to do TC or Clutch work. In the picture you show, it is low enough to remove the diff without taking the entire tunnel out.
ahhh yes, the picture. I see where you are coming from now. My pic may be misleading; the front of the torque tube has been unbolted from and pulled off of the engine. You just can't see it in the pic.
The position of the tranny jack makes the transaxle unballanced; being rear heavy. When I slid the torque tube off the engine crankshaft, it went up... resting against the top of the tunnel; instead of falling down... due to the leverage of the rear heavy condition pivoting on the trans jack. (kinda like a teeter totter with a heavy kid on the other side :) ) As I lowered the now loosened transaxle; the front of the torque tube remained up against the top of the tunnel because of the unballanced condition.
From the lowered position in the pic, I was able to do the carrier swap since I now had the clearance necessary behind the carrier.
My point is that when you get the tunnel dropped down far enough to remove it, you have it far enoungh down to slide the diff off the
when you get the transaxle/torque tube assembly completely unbolted and pulled off the engine, you can now lower it far enoungh down to slide the diff off the off the transmission.
[Modified by Mike Mercury, 11:46 AM 3/2/2002]
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From: Hendersomville NC
Re: Rear diff swap DIY advised? (Mike Mercury)
Mike:
It did look a little lower than possible when bolted up. I will have to take a close look when I get into it, definitely do not want to damage the firewall, but do not want to do more work than necessary. I will be working off a lift so might have it a little easier supporting and manipulating the tunnel/tube tranny diff assembly. We'll see.
Thankls for all of the input and congratulations on a good job. I love to see DIY success stories.
Take Care,
Alan
It did look a little lower than possible when bolted up. I will have to take a close look when I get into it, definitely do not want to damage the firewall, but do not want to do more work than necessary. I will be working off a lift so might have it a little easier supporting and manipulating the tunnel/tube tranny diff assembly. We'll see.
Thankls for all of the input and congratulations on a good job. I love to see DIY success stories.
Take Care,
Alan
