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4T60 Swap - Observations & Comments: by Cajun
Started on: 10-28-2015 03:01 PM
Replies: 15 (582 views)
Last post by: Cajun on 11-02-2015 05:03 PM
Cajun
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Report this Post10-28-2015 03:01 PM Click Here to See the Profile for CajunClick Here to Email CajunSend a Private Message to CajunEdit/Delete MessageReply w/QuoteDirect Link to This Post
For some time now I have been considering doing a 4T60 swap on my ’86 GT. But, for whatever the reason, it has taken me about 5 years to get around to it. Other projects on the car took priority; Digital HVAC system, 2002 Camaro/Firebird BCM swap, etc. You are familiar with the exercise, first one thing than another.
For starters, I have had the transmission for about 5 years now, more or less only recently was I inspired to complete the swap. My motivation was several factors; 1) I was participating in the Crusin’ the Coast held recently and secondly I plan on doing the “Hot Rod” Power Tour 2016 this coming June. Oh, another driver for the swap was the fact that most of my driving is at highway speeds and thought it was ludicrous doing 70 mph at just under 4,000 RPMs.
I had located a thread here on the forum about doing a transmission swap without dropping the engine. Ok, said to myself, that sounds doable. So, here we go the beginning of the 4T60 swap. It didn’t take too vary long before I realized that this approach was not the best. Besides, I was not in the mood for cutting bracket supports. I later discovered a thread by Toddster, “Removing a V-6 Engine – By the Numbers. ( By the way, thank you Toddster for that very well presented thread.) I went through the thread and soon found out that I had already completed about 90% of the work that was described in Toddster’s thread. So, what the heck let’s see if we can accomplish this. After all, all that was remaining for dropping the engine and the transmission was disconnecting the coolant hoses, one or two electrical connections, disconnecting the ECM then we are ready to do the removal. Also, while I had the engine out I figured I would go ahead and address other items that I had identified that needed addressing. I.e.: replacing the A/C compressor, installing the belt tensioner by Dodgerunner, water blasting the cradle and engine to remove almost 30 years of dirt, grim and slug. I also checked the spark plugs (the front ones) to see what condition they were in, they were clean. No carbon buildup. In fact the ceramic on the plugs was still white. The plugs are 3 years old. Also, while I was at it did a compression check on the engine; all cylinders were within 5 lbs. of each other.
My 4T60 by the way is one out of a ’90 Toronado with 2.84 gears. I did replace all of the seals before installing. Also replaced were the transmission mounts & brackets, engine mount, CV’s, etc. Here is a listing of the parts used and where purchased:

1. Transmission mounts – RockAuto
2. Motor mount – RockAuto
3. Modulator – RockAuto
4. Replacement TV cable – Rodney
5. Cradle bolts – The Fiero Store - did not use
6. Transmission seals – RockAuto
7. Vacuum hoses – AutoZone
8. New HR6 A/C compressor – RockAuto
9. CV's - EBay
10. Hi-Lo A/C compressor switches – Advance Auto
11. Exhaust hanger - Driver side - The Fiero Store
12. Transmission oil line hoses - AutoZone


During the re-assembly I found out that the total engine/transmission drop was the better choice. To properly install the engine to transmission bracket it was necessary to remove the alternator. With everything being out this made the installation easier. As mentioned earlier I utilized my existing engine to transmission bracket. All that was required that the bracket be relocated to the bolt holds on the engine block to the right of the existing bolt hoses. Then elongate the transmission mounting holes slightly. Worked for me!

The one issue that I did have and have yet to truly resolve has to do with the VSS unit. I was never able to locate a unit that was compatible with the Fiero. My plan B was to utilize a interface module from Dakota Digital. That works but not my preference. I do happen to run across a VSS that is compatible in the future that puppy is going in.

Issues:

1. Upon testing, on the road, the transmission I was having shifting issues but was later resolved by watching a couple YouTube videos about adjusting the TV cable. The transmission now shifts at set points I’m comfortable with.
2. Transmission oil leak. Again when road testing the transmission developed a pretty severe leak. When stopped the leak was non-existent. Start engine and put into gear without moving, no oil leak. I made another short road test down my drive way. Yep, again an oil leak. Hauled the car back onto the shop to begin yet another tear down. The leak was on the passenger side. During the dis-assembly I noticed that the CV would move slightly only to discover the snap ring had not set. CV set, snapped into place, oil leak resolved.

Benefits:
1. If I would have known earlier how much better the car runs I would have done the swap years earlier. Now I do highway speeds (70ish) with the engine turning a little over 2100 RPMs.
2. Did I mention gas mileage improvement? I went from 26-28 MPG to about 40 MPG. I’m liking the swap even more with the improved gas mileage. I recently did a road trip with the new transmission (Ruckus 14) and was averaging in the 40 MPG range.
3. I have put about 800 miles on the transmission since the installation without any issues or problems; I feel I’m ready for the Hot Rod Power Run come 2016.
4. I was going to install a rebuilt 3.4 engine out of a ’95 Camaro but held off due to the condition of my existing 2.8. Dollar savings

[This message has been edited by Cajun (edited 11-06-2015).]

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Gall757
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Report this Post10-28-2015 03:59 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post


Good to know how it all worked out. 40 mpg with a 2.8 is just about unheard of, and many 4T60s likely won't do that well because there are many different final drives available, but you have nicely documented one way to get there.
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Patrick
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Report this Post10-28-2015 04:24 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Cajun:

...water blasting the cradle and engine to remove almost 30 years of dirt, grim and slug.


Ewwww...



 
quote
Originally posted by Cajun:

Did I mention gas mileage improvement? I went from 26-28 MPG to about 40 MPG. I’m liking the swap even more with the improved gas mileage. I recently did a road trip with the new transmission (Ruckus 14) and was averaging in the 40 MPG range.


40 MPG is awfully difficult to believe for a 2.8, even with a 5-spd manual... but with an automatic???
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Dodgerunner
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Report this Post10-28-2015 05:06 PM Click Here to See the Profile for DodgerunnerClick Here to visit Dodgerunner's HomePageClick Here to Email DodgerunnerSend a Private Message to DodgerunnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
Man this sounds like me. I have a 4t60 that has been setting for 5 years I keep looking at wanting to put it in my 88GT. Hate those RPMs.
I'd like to know more about the mounts. Did you have to modify the cradle at all? Use completely different mounts?


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Report this Post10-28-2015 05:34 PM Click Here to See the Profile for tsharkSend a Private Message to tsharkEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

40 MPG is awfully difficult to believe for a 2.8, even with a 5-spd manual... but with an automatic???


That 800 miles was a world record down hill.
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Dodgerunner
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Report this Post10-28-2015 05:43 PM Click Here to See the Profile for DodgerunnerClick Here to visit Dodgerunner's HomePageClick Here to Email DodgerunnerSend a Private Message to DodgerunnerEdit/Delete MessageReply w/QuoteDirect Link to This Post
I got 37 with my 3.4 and 4 speed manual in the Rocky's. Going down hill and having the ecm shut the injectors off made it happen.

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Cajun
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Report this Post10-28-2015 06:00 PM Click Here to See the Profile for CajunClick Here to Email CajunSend a Private Message to CajunEdit/Delete MessageReply w/QuoteDirect Link to This Post
I figured the 40 MPG would raise eyebrows. But that is what the math indicates.

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Cajun
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Report this Post10-28-2015 06:07 PM Click Here to See the Profile for CajunClick Here to Email CajunSend a Private Message to CajunEdit/Delete MessageReply w/QuoteDirect Link to This Post
Dodgerunner,

For the transmission mounts, all I did was elongate the existing holes in the cradle about 1/2" to 3/4". The transmission brackets came off a '89 GM vehicle. Don't remember the model. As for the mounts themselves were stock '86 Fiero.

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Patrick
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Report this Post10-28-2015 06:52 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Cajun:

I figured the 40 MPG would raise eyebrows. But that is what the math indicates.


For what time period? A matter of months with many many fill-ups... or one trip?

IMO it's too easy for the figures to be accidentally fudged with one or two fill-ups due to variances with how full the tank is made with different gas nozzles etc.

[This message has been edited by Patrick (edited 10-28-2015).]

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Cajun
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Report this Post10-28-2015 07:24 PM Click Here to See the Profile for CajunClick Here to Email CajunSend a Private Message to CajunEdit/Delete MessageReply w/QuoteDirect Link to This Post
Multiple fill ups over a 4 day period. First two or three fill ups were done at my usual 175 tripometer readings. After I realized I were getting better gas mileage I began doing tank ups at around 200 to 250 miles. The longest run that I recorded was 217 miles. The tank up took 5.23 gallons. That was with gas pouring out. I tried to be very concise ant with the fillup method.

Regardless, I'm very pleased with the results.

End of discussion on this subject.........
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Patrick
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Report this Post10-28-2015 07:52 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Cajun:

End of discussion on this subject.........


Yes sir!

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Report this Post10-29-2015 10:02 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:
40 MPG is awfully difficult to believe for a 2.8, even with a 5-spd manual... but with an automatic???

Because V6 5 speeds have 3.61:1 final drive. TH125 for V6 and Many 4Txx(E) trans have low "finals" too.

I believe his MPG are accurate base on math in my cave alone...
See my Cave, AOD Convert

If above have Locking TC or not will affect MPG too.
Locking TC on the highway will improve MPG on all auto trans cars.

Example: DIS duke and TH125c 2.84 Transaxle Ratio (RPO=F17) I get ~30mpg for long trips because TC is locked most times. Drive local and TC doesn't lock often to rarely and never get over ~25mpg.

Saving gas by changing gear setup could cause problems...
If you use allot of electric power then the Alt might not keep up now when you have OD (4th gear).
Advertise Amps for alt is Peak Amps... Low Engine RPM then Low Alt RPM too and makes less power.
Is same issue using "power pulley." See my Cave, Watt Story

Local driving you can run 4Txx trans in 3rd gear all the time w/o problems. If you setup TC locking correctly then will lock in 3rd gear too. (125 and 4T60 are 1:1 3rd gear. See my Cave, Gear Ratio)

ETA: All Fiero MPG are listed here... (fueleconomydb.com)
I see my number match highway and combined most weeks for 87 w/ dis duke & auto trans.
Click on a car to get old values. I'm close to match highways and city for old method.
(New EPA rules are more close to real world MPG. 2008 update was to address Hybrids cars and their inflated #.)

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)


The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 10-29-2015).]

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Cajun
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Report this Post11-01-2015 02:45 PM Click Here to See the Profile for CajunClick Here to Email CajunSend a Private Message to CajunEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thought that I would post a coupe of photos regarding my recent 4T60 swap.

This one is with Dodgerunner's belt tensioner installed:



This one is the engine to transmission bracket. As mentioned earlier, I used the stock bracket for the swap.

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Report this Post11-02-2015 02:34 PM Click Here to See the Profile for lou_diasClick Here to Email lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
Some people have all the luck!
my 4T60-E won't go past 3rd... Does 75mph @ 2950rpm...
Somehow I remember my 86GT 4spd doing 65 @ 3000 so I guess it's a slight improvement...
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Report this Post11-02-2015 03:51 PM Click Here to See the Profile for johnyrottinClick Here to Email johnyrottinSend a Private Message to johnyrottinEdit/Delete MessageReply w/QuoteDirect Link to This Post
Cajun, knowing what you know now how long would you say this swap over should take?
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Cajun
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Report this Post11-02-2015 05:03 PM Click Here to See the Profile for CajunClick Here to Email CajunSend a Private Message to CajunEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would say if you have all the necessary parts, tools and assistance the swap can easily been accomplished in a weekend, if not less! My swap, on the other hand took about 3 weeks. I had to wait for parts to arrive and for my son to help with the install.

I was able to pull the cradle in about 3 hours. The re- install took about an hour, then another 2-3 hours to hook everything back up, refill the coolant, burp the system and refill transmission with oil.

A single person can pull the cradle, however assistance is needed for the install. While raising the cradle into place someone needs to guide the shock towers into place.

In my case, I was not in any rush.

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