1995 Impala SS - Transmission Issues

[LT1Silverhawk]

Hi All,

I’ve got two questions related to a transmission issue with my ’95 Impala.

The specs on the car are: 383 LT1, fully built 4L60E auto transmission, and a built rear end with 3.90 gears. I don’t have the specs or records on any of the builds as they were done by the previous owner who sold the car to a local shop after an accident.

Yesterday, I gunned the car from a slow start and then heard a loud bang. The car was no longer getting any power to the wheels. I brought the car to a safe stop, put the transmission into park, turned the engine off, and then restarted it. I shifted through the gears and found that the engine was revving fine but still no movement in any gear.

I’m a total rookie when it comes to transmissions but, between my neighbor and me, we think it is one of two things: the transmission is shot or the torque converter is damaged.

Second question is, should the transmission turn out to be no good, any ideas of a good replacement transmission? I’m considering a T56 swap but have not been able to find any posts on this site that discuss how to do it.

I must add that I am on a budget so if it turns out to be too much, I may have to just sell the car as is.

I had the car towed to a local shop for a diagnosis. In the mean time, I thought I’d try and pick the brains of all the smart folks here.

What do ya’ll think?

Thanks in advance for any help…

[j cAT]

I would bring to a repair shop and have the tranny opened up and see exactly whats damaged..could be a simple part change that snaped like a pretzel.

since the tranny was working fine prior to this it should not need a rebuild..Also since it is possible that the tranny has non OEM parts it is possible this is the reason this bang suddenly occured..

post back with your findings..

[LT1Silverhawk]

Originally Posted by j cAT

I would bring to a repair shop and have the tranny opened up and see exactly whats damaged..could be a simple part change that snaped like a pretzel.

since the tranny was working fine prior to this it should not need a rebuild..Also since it is possible that the tranny has non OEM parts it is possible this is the reason this bang suddenly occured..

post back with your findings..

I was hoping you’d respond j Cat!

Of course, all other help is more than welcome!

I am expecting a response from the shop this week.

Unfortunately, as much as I trust the shop, I don’t trust the transmission shop they contract with for transmission repairs. The reason I took it to them anyway is because I am hoping they will give me a good diagnosis while I look for a reputable repair shop.

Would it be a bad idea for a rookie like me to drop the transmission, open it up myself, and take pictures for reference before going to a shop? After dealing with the last transmission rebuild on my Camaro, I am super nervous about dealing with any shop at this point.

Thanks j Cat… your tips and insight are helpful as always…

[maxwedge]

Unless you are very mechanical and have the proper tools and a lift, I would not suggest tackling this, plus you do not know what was done and being inexperienced you would not be able to determine what is original and what has been changed/modified.

[LT1Silverhawk]

Originally Posted by maxwedge

Unless you are very mechanical and have the proper tools and a lift, I would not suggest tackling this, plus you do not know what was done and being inexperienced you would not be able to determine what is original and what has been changed/modified.

Thank you MaxWedge, you make an excellent point there.

My mechanical abilities are very limited when it comes to engine and transmission removal and installation.

However, I do have access to several 2 ton jacks, jack stands, an engine hoist and a host of tools. I expect that if I can get a good shop manual, I should be able to remove the transmission properly and safely.

My intention is not to determine what happened, because I sure as heck would not know what to look for, as you pointed out. But what I do want to do is to remove the transmission, open it (if that will not damage anything) and take pictures to use for reference before handing the transmission off to a shop.

The reason for doing all this on my own is that my last transmission rebuild through a shop was a horrible experience and I am afraid I may have been screwed over pretty bad.

At least with pictures in my hand, I may be able to get better input from other people as well before making a decision.

I really wanna do this right the first time.

BTW, any thoughts on a good replacement transmission or a T56 swap?

[maxwedge]

Remember to get it high enough for the bell housing to clear the frame, aslo some jacking device to hold and roll the trans out, I would also suggest a trans manual from atsg.com

[LT1Silverhawk]

Originally Posted by maxwedge

Remember to get it high enough for the bell housing to clear the frame, aslo some jacking device to hold and roll the trans out,

I was thinking of buying a transmission jack but I think the local Harbor Freight carries adapters for regular floor jacks.

These are the two that I found:

2-ton jack adapter http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39152

3-ton jack adapter http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95640
　
　
　

Originally Posted by maxwedge

I would also suggest a trans manual from atsg.com

Thanks! That’s a good site to know. The links below are to the books I feel best meets my needs. Apparently there is an “Update Version” that is required.

Original Guide: http://atsg.com/cart/products/4L60E-21-5.html
　
Updated Guide: http://atsg.com/cart/products/4L60_E_4L65E_Update_Handbook-75-5.html
　

Thanks for the continued help!

Now I just need to get over my fear and nervousness...

[maxwedge]

The trans jack adapter works ok, but it makes very tough to roll the trans out from under the car as it requires more height, so watch out for that.

[LT1Silverhawk]

Originally Posted by maxwedge

The trans jack adapter works ok, but it makes very tough to roll the trans out from under the car as it requires more height, so watch out for that.

I’m glad you brought that up as I had not thought of it yet.

I realize there may be no way for anyone to know an answer to this without actually jacking up the car, but how high should the car be off the ground so the bell housing to properly clear the vehicle’s frame?

I think, with the jack stands I have now (standard Sears material), I can lift the car a little more than a foot off the ground. Otherwise I’ll try to get taller jack stands.

[maxwedge]

You will need to get this up more than 12".

[LT1Silverhawk]

Originally Posted by maxwedge

You will need to get this up more than 12".

I think my floor jacks are good for about 2 feet of lift (standard Sears 3 ton). So I can get taller jack stands and get some good clearance. I guess the one thing to add to the height of the transmission's bellhousing is the height of the floor jack and adapter.


Just browsing the Harbor Freight site again and found:

3 ton jack stands (good for 16" clearance) http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38846

6 ton jack stands (good for 24" clearance) http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38847

[MagicRat]

LT1, hold on for a moment.

Before you do this, consider a couple of points.

1. If you re and re your own transmission, then you are responsible for removing it again if there is a defect in the rebuild..... even if the rebuilder is at fault. This happened to me once. It's really annoying to re and re a second time due to no fault of my own.

If you send it to a mechanics shop for the re and re, then they are responsible for removing it again, at no cost to you, if there is a defect that needs fixing.

Have you ever removed a transmission before? If not then, without a hoist and a couple of buddies, its a bitch. It's easy to drop the trans and damage the housing and/or injure yourself. If you enjoy the challange of working on your own car, go ahead and do it. But otherwise, let the rebuilder do it.

2. I strongly suggest against disassembling your transmission. Unless you know about auto transmissions, diassembling one is like taking an alien spacecraft apart. Many of the components, their function and disassembly are completely unfamiliar. At the very least, you will need a good tramsissison rebuild manual to take it apart (Haynes makes one).

You will also need special circlip pliers and a unique transmission spring compressor to disassemble. Trust me, rebuilders hate getting a basket of parts. Parts can be lost of damaged during disassembly. You need to keep track of many many small parts. Some parts MUST be reassembled in the same order that they came apart. Even if you keep track of them, a rebuilder may not understand your system of keeping track of this stuff and screw it up. A rebuilder may blame you if something is lost or damaged, even though it may be their fault.


Also, the rebuilders ability to diagnose the fault is impeded because they cannot inspect the components in their as-found condition for things like end-play or tolerances.
Finally, there may be a warranty issue if you have done some disassembly on your own.
IMO if you want a good rebuild experience, look around for a reputable shop. Ask them for references and speak to some of their customers. Let them do the entire job, including removal. This makes determining the responsibility of repair and warranty coverage much, much easier.

[LT1Silverhawk]

Originally Posted by MagicRat

Before you do this, consider a couple of points.

1. If you re and re your own transmission, then you are responsible for removing it again if there is a defect in the rebuild..... even if the rebuilder is at fault. This happened to me once. It's really annoying to re and re a second time due to no fault of my own.

If you send it to a mechanics shop for the re and re, then they are responsible for removing it again, at no cost to you, if there is a defect that needs fixing.

Have you ever removed a transmission before? If not then, without a hoist and a couple of buddies, its a bitch. It's easy to drop the trans and damage the housing and/or injure yourself. If you enjoy the challange of working on your own car, go ahead and do it. But otherwise, let the rebuilder do it.

I completely agree with you on the whole r&r deal. I do enjoy the challenge of working on a car but my biggest concern is getting ripped off again on the rebuild.

So far, I personally have not been able to find any shop that I have a good feeling about. The last rebuild on my Camaro was shoddy and I would take the Impala back to the shop that originally built it up but (j cAT, you probably remember this from helping me out before with the oil burning issue) “The Shop’s” owner himself seems a bit shady.


Ok, side-story time…

Interestingly, the Camaro (1993 LT1, 4l60/700R4 transmission) that had the transmission rebuilt apparently had the same thing happen as my Impala, except with a different owner. The guy who sold me the Camaro said his brother driving on the freeway when, all of a sudden, he heard a bang (just like in the Impala), and the car was no longer getting power at the wheels.

When I took the Camaro in to my local trusted mechanic shop, they shipped it to a contractor who rebuilds transmission for them. They had nothing but high praise for this contractor: reliable work, 12 month / 12,000 mile no-questions-asked warranty.

The Contractor did not pick up the car for a good week.

After he took the car, the first thing The Contractor did was call back, saying the transmission was frozen and would he need another core for a rebuild for an additional $100. Not having any knowledge, I agreed to it.

The Contractor took his sweet time on the rebuild. As soon as I got it back, I noticed the car just wasn’t moving fast. Felt more like my friend’s V6.

So the shop sent it back and the transmission was “rebuilt” again. On the test drive, the good ‘ol Opti-Spark died.

After the Opti-Spark was replaced (which is another story in itself), we went for another test drive and still, the car felt week. I asked around and a local transmission rebuilder who happened to be at AutoZone said it was the wrong torque converter.

So, I took the car back to the shop and told them it seems like The Contractor used the wrong torque converter. They shipped it off again, informing The Contractor that I said there was an issue with the torque converter.

Again, the Contractor took his sweet time, sent the car back and this time, it felt powerful. But the transmission pan gasket went bad – twice. This was about a year ago this month.


I am continuing to ask around while waiting for an answer from my local shop where the car is presently sitting. I am considering going to local performance shop, Team C Performance. They tend to be on the pricey side about everything but also seem quite knowledgeable. But a coworker also recommended a family member who is ASE certified and is well-versed in GM vehicles. He is charging $400 ballpark for the labor if I provide the parts.

Originally Posted by MagicRat

2. I strongly suggest against disassembling your transmission. Unless you know about auto transmissions, diassembling one is like taking an alien spacecraft apart. Many of the components, their function and disassembly are completely unfamiliar. At the very least, you will need a good tramsissison rebuild manual to take it apart (Haynes makes one).

Aside from the fact the auto transmissions shift automatically, have fluid, a filter, a pan and a torque converter, I don’t know a damn thing.

MaxWedge was very helpful in recommending ATSG for a good transmission manual for a through walk-through. A little research showed that there are some detailed DVDs available as well (How detailed? I don’t know).

Originally Posted by MagicRat

You will also need special circlip pliers and a unique transmission spring compressor to disassemble. Trust me, rebuilders hate getting a basket of parts. Parts can be lost of damaged during disassembly. You need to keep track of many many small parts. Some parts MUST be reassembled in the same order that they came apart. Even if you keep track of them, a rebuilder may not understand your system of keeping track of this stuff and screw it up. A rebuilder may blame you if something is lost or damaged, even though it may be their fault.

Originally Posted by MagicRat

Also, the rebuilders ability to diagnose the fault is impeded because they cannot inspect the components in their as-found condition for things like end-play or tolerances.
Finally, there may be a warranty issue if you have done some disassembly on your own.
IMO if you want a good rebuild experience, look around for a reputable shop. Ask them for references and speak to some of their customers. Let them do the entire job, including removal. This makes determining the responsibility of repair and warranty coverage much, much easier.

Again, good points.

I feel that if I can find someone who will give a correct diagnosis with no intention of ripping me off, I’ll be more than happy to let them deal with the entire process from beginning to the end.

However, from a "desire to learn perspective”, I may be better off going with my co-worker’s recommendation and be a small part of the process so I can at least observe what goes on in such a project.


As always, thanks for the continued help and support and letting me rant. I've learned quite a bit already...

You guys are awesome!

[MagicRat]

Yes, that experience does seem to suck a bit. Have you considered a performance transmission from an on-line supplier, if there are no decent shops avaialble locally?

The reason why I ask is that a rebuild shop may charge you extra for replacing broken hard parts. If this is the case, you may be able to save a couple of bucks by getting a rebuilt transmission on exhange.... and its much faster, too.

The 700R4 / 4L60 series seem to have a couple of weak mechanical parts, such as the annulus (ring) gear in one of the planetary gear sets. These things break with a bang and cause you to lose all gears instantly. It happened to me, with a 700R4, and I just had a weak 305. And yes, I took my own transmission apart, with the thought of rebuilding it. When I found the ruined gearset, I just located a used 4L60 (not an 'E') for $150 and swapped it in.... much cheaper in the long run.

I think you can get aftermarket gear sets which are stronger than stock. Some on-line rebuilders may offer such upgraded parts in their transmissions.

[LT1Silverhawk]

Originally Posted by MagicRat

Yes, that experience does seem to suck a bit. Have you considered a performance transmission from an on-line supplier, if there are no decent shops avaialble locally?

Originally Posted by MagicRat

The reason why I ask is that a rebuild shop may charge you extra for replacing broken hard parts. If this is the case, you may be able to save a couple of bucks by getting a rebuilt transmission on exhange.... and its much faster, too.

I have considered buying a performance transmission online but haven’t done any serious research just yet. As jcAT pointed out, it may just be a simple part and the entire transmission may not need to be replaced. So I am waiting to find out exactly what is wrong before I start looking around.

There are lots of local shops, but I am struggling to find one with an excellent reputation. In these economic times, many people seem to be cutting corners to make a quick buck.

Originally Posted by MagicRat

The 700R4 / 4L60 series seem to have a couple of weak mechanical parts, such as the annulus (ring) gear in one of the planetary gear sets. These things break with a bang and cause you to lose all gears instantly. It happened to me, with a 700R4, and I just had a weak 305. And yes, I took my own transmission apart, with the thought of rebuilding it. When I found the ruined gearset, I just located a used 4L60 (not an 'E') for $150 and swapped it in.... much cheaper in the long run.

Originally Posted by MagicRat

I think you can get aftermarket gear sets which are stronger than stock. Some on-line rebuilders may offer such upgraded parts in their transmissions.

It would be cheaper to find a used 4L40E and replace it bad one but I need one that can handle the stroker’s power. And therein lies one of my biggest challenges: finding the right combination of parts that reliably handle the power. I’ve seen several prepackaged kits from Trans-Go, TCI and B&M but don’t know which one to go with.

There is also PATC that seems to offer a pretty sold transmission:

http://www.transmissioncenter.net/4L60E.htm


On a side note, the transmission in the Impala shifted pretty hard from 1 - 2, and 2 -3. "The Shop" owner said this was because the transmission was built a step below a racing transmission, hence the hard shifting. But this thing was a real back breaker. Daily stop and go pretty much killed my back to be point that I've considering selling the car. With this opportunity in hand, I'd like to able to modify it so it doesnt shift so hard under normal driving.