456 Auto Gear Box transmission problem | Page 2 | FerrariChat

456 Auto Gear Box transmission problem

Discussion in '456/550/575' started by HKFerrariLlover, Jul 22, 2010.

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  1. Yukon42

    Yukon42 Rookie

    Dec 22, 2013
    8
    Vegas
    Full Name:
    Mike
    #26 Yukon42, Jan 11, 2014
    Last edited: Jan 11, 2014
    Sure would be interesting to know how the problem was solved or IF it was solved. I PM'd the OP. If I get an answer, I'll post it here.
     
  2. HKFerrariLlover

    Oct 11, 2009
    37
  3. ChipM

    ChipM Rookie

    Jan 1, 2013
    40
    Spartanburg, SC
    Full Name:
    Chip McLeod
    I know some of these posts are old, but I thought I'd chime in. I am the SC FCA Chapter president - I have two F-cars (one being a 98 456 GTA) and do all my own work. I have just put the transmission back in so here are my observations. I ended up removing it due to a noise. I had pulled the torque tube down last year and put bearings in it but it still made the noise. Turns out the torque converter was coming apart on the inside and I had it rebuilt and rebalanced. Much more about that (and pictures) at a later date. Anyway, as mentioned, the two "scavenger" filters are in the bottom, easily accessible through the pan. The two shift solenoids (also GM parts) are in there too. The rear filter is considered the main filter, and probably the most important, but also the most difficult to get to (typical Ferrari...). The rear bumper must be removed (absolutely a two person job), as well as the oil cooler. Once you have the back cover off, the other two solenoids (TCC and pressure) are easy to change - these are also GM parts. If you Google 4T80E solenoids, any of the big transmission houses have them. Since I was this deep, I changed them. The oil pump is also accessible from here and it appears to have GM internals too. As stated above, the two gaskets have to be Ferrari, not GM, because of the different configuration of the trans by Ricardo for Ferrari. I know there are horror stories and people scared of the GTAs due to the tranny, but it appears as robust as any other to me. I figure if I treat it well, don't abuse it, and do the complete service every time I do a major and belts (every six years for me) it will last. In full disclosure, I am not a professional mechanic and do not turn wrenches for a living, and this info is simply to help with your research and due diligence.
     
  4. ChipM

    ChipM Rookie

    Jan 1, 2013
    40
    Spartanburg, SC
    Full Name:
    Chip McLeod
    456 GTA Driveline/transmission noise - I know lots of these are old threads and this will be a long post but maybe this info will help others. I have recently posted about working on the torque tube and autobox of my car, so this is a more detailed write up. I have a 98 456 GTA (a very late non-M). It has had a small noise in the driveline since I bought it. The noise is not a grinding but an intermittent "rattle", almost like a loose marble somewhere, then quieter other times, not noticeable to anyone but me. I happens in P, R, D, although it did seem worse sitting still in D with a foot on the brake. Last summer after ruling out exhaust, shields, etc., I decided to pull the TT (torque tube) down after reading about the bearings in it. Both autos and 3-pedal cars have the tubes, although the shafts and bearings are different. I had it up on a lift and moved the transaxle back as far as it would go. It is a job but I got it down. Once the TT was out, the bearings looked OK, although it is hard to tell. I even spun the shaft up to idle RPM but couldn't tell. Anyway, I sourced out SKF bearings, then removed the inner and outer rubber and put them on the new bearings. The OEM bearings are hard to find and $$$$. All went back well so I had high hopes. Got it back in and took it to Chattanooga, and Charleston, SC for FCA events. The noise was still there, but maybe different. As you know by this time you are straining to hear anything! After concluding that the only other two things that turned in park or while not moving were the TC (torque converter) and whatever kind of pump they were using in the trans, I decided to pull it down. I bought a 1 ton engine lift (cherry picker) from Harbor Freight and used the base and cylinder to fashion a transaxle jack. That thing is VERY heavy so you have to have something. I did the same as last summer: remove bumper, oil cooler, half-shafts, wires, shift cable and slid it back. I pulled the TT down to recheck it. You also have to remove most of the exhaust. After some more work I got the transaxle down on my homemade jack. The next big job was getting the TC out. The ring nut is left-hand threaded and has factory red loctite so it was a bear to get off. I ended up having to make a socket with 4 tabs (picture attached), then make a bracket to hold the socket. I heated it some, but more heating may have broken it better. I hoped again to find something obvious like the flex plate being loose or cracked, but it was all perfect. The two "nose" bearings at the front of the housing behind the nut looked OK too, although my heating and beating on the ring nut did them in; I was going to replace them anyway and they were an easy match. I sent the (44lb!!!) TC to Ron (the owner) at Gene Browns transmissions in Houston, TX. I had read about him and seen some of his work. I talked to him on the phone first and was satisfied that he knew what to do. After some anxious days passed he called me. He said the old plate (looks like an old asbestos clutch or lock-up plate) was coming apart and would probably be making a shuttering noise or a rattle. I was never so happy to find out about a problem! He said the technology had improved a lot over the last 20 years and he would put in all seals, springs, bearings, and a new kevlar plate. He also said it was very out-of-balance; could have been Ferrari just using off the shelf GM TC parts, or it may have been dropped in shipping down there - and that he would rebalance it. I approved happily of the repairs (around $500 - a deal I thought after all that). As I waited on it to be returned I decided to dig a little more into this mysterious transmission that scares people. It is indeed very similar to a 4T80E. I replaced the solenoids: the 2 shift ones are in the bottom, and the TCC and pressure solenoids are under the back cover with the main filter (picture attached). All 4 of these are GM/Delco units, as well as the 3 filters - the main one in the back and the two "scavenger" ones in the pan. The fluid pump is also under the rear cover and it appears to be GM also (picture attached). The old unit seems pretty robust. I also replaced the two transaxle mounts that sink over time like the front motor mounts. I put it all back together and the car runs and shifts great. And best of all, all of the noise is gone. So here is my two cents worth: if you have a noise and take it to a shop, I would replace the TT bearings, pull the autotrans down (which they will probably end up doing anyway) and correctly fix it. Put the two bearings in the front of the housing, send the TC to Ron in Texas, and replace the 3 filters and 4 solenoids. Put one quart of Mobile full syn ATF in the TC and about 11 or 12 more in the transmission. For a little extra time and money (while you are in there), you will have covered all the bases, have an updated, balanced TC, and have a fully serviced trans. I am not a professional mechanic and this is not my day job - this is just intended to be info to help. Then to really make it a great car get the cats out, switch out the rear exhaust cans, bypass the immobilizer, send the window mechanisms to F1 in Florida, put in updated 575 motor mounts, put in a 34R redtop on a tender, etc........
     
  5. leadingedge

    leadingedge Rookie

    Jun 16, 2015
    3
    How long did it take you to pull down the TT to check the bearings? Was it a huge pain or relatively easy?
    Thanks!
     
  6. ChipM

    ChipM Rookie

    Jan 1, 2013
    40
    Spartanburg, SC
    Full Name:
    Chip McLeod
    It’s a big job. The entire transaxle has to slide back so that’s bumper off, oil cooler out, halfshafts out, exhaust down, etc. best to do it with a lift.
     
    crinoid likes this.
  7. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    26,289
    socal
    Well done Chip! Do you have part numbers for the solenoids and filters? If they are GM sourced parts can you put them in the parts interchange thread?
     
  8. ChipM

    ChipM Rookie

    Jan 1, 2013
    40
    Spartanburg, SC
    Full Name:
    Chip McLeod
    Took at while to dig this info up. It is a very close cousin to the GM 4T80E. The four solenoids can be sourced online (at any big transmission house) or at parts houses. The 456 auto box takes the two shift solenoids in the bottom - standard 4T80E with updated brackets. The other two are in the rear, the EPC (pressure) one and the TCC (torque converter) one, also 4T80E. To change the rear ones requires removal of the rear bumper and oil cooler. While in there you can change the main filter, also GM. The two shift ones are in the bottom with the two scavenger filters (GM). This can be accessed from under the car by removing the pan; however, it is more difficult than it looks. The entire valve body (also GM) has to come down and come apart, then the two shift solenoids go in the top of the valve body. Because you could get to it anytime, I would not change the shift solenoids until needed.
     

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