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4L80E behind 4.3 V6?

22K views 20 replies 6 participants last post by  Torque454 
#1 ·
I bought a Volvo 265 stationwagon back in March of this year. It has a chevy 4.3 v6 and a 700r4 transmission. The engine is low mileage and the transmission has been rebuilt. HOWEVER. This was all done in about 1999 and the car has sat as a spare vehicle (in a garage) since then. The tires which were brand new in 1999 and had almost no miles on them, all have blown out since then so age has definitely taken its toll on this car.

The problem is that now the transmission is acting wierd. Shifting quickly and yesterday was slipping. I discovered the fluid was low, so I added a couple quarts and it seems to have stopped the slipping but the transmission is stilling shifting and acting unusual. I fear the worst which is that the transmission is going out, even tho it has 15,000 miles or less on it.

The transmission was rebuilt with a bunch of corvette parts and stuff. All the goodies, in an attempt to make it shift better (rebuilt transmissions never shift as soft as they did from the factory).

I've had great luck with the 4L80E in my 96 suburban. It has 300,000 on it and never even had the fluid changed, let alone anything else. How well would a 4L80E work behind a 4.3L V6 (1997 model Vortec, 200hp/250ft lb) and would the 97 S10 computer that was used work to control the 4L80E? Or should I just stick to another 700r4? Perhaps this one could be fixed and not have to be rebuilt again?? I am wondering if maybe I can still save this one, but if not, id really consider a 4L80E. Such a waste of a good transmission for that dinky little car tho. Love the car, and it doesnt need a 4L80e..... BUT... its such a good transmission and this car needs a good transmission that is going to last more than 15k miles...
 
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#2 ·
Do you think the 4L80 will fit? Take a few measurments. I bet it will require a lot of tunnel surgery to get it in there.
About the current 700 R4. You said is was rebuilt "with a bunch of Corvette parts" There is the reason it is shifting a bit harder. Corvetter servo probably and a probable shift kit will make it hit a bit harder on up shifts. If you don't know that much about adjusting the TV cable a search here will get you that info. If you don't want to mess with it take to a REPUTABLE trans shop and have it serviced and checked out. new fluid and filter may do it wonders.
Mark
 
#5 ·
I don't know if a 4l80e will fit or not. I didn't think about that. There is a ton of room around the firewall/bellhousing area tho. I do not know what corvette parts were used, I was just told by the guy that did the swap that it had corvette stuff in the transmission. He saved all the receipts from the work he had done to the car and gave them all to me so i might be able to look it up and see what was done to it. However, he told me that the corvette stuff was installed later on, because of how it shifted after it was rebuilt. I guess I will take it back to the transmission shop that rebuilt it. They are well known in the area, do only automatic transmissions, and have a shop with 6 or 8 bays and they are always full. I'd assume they must be pretty good or they wouldnt be so busy all the time. May be time for a new filter I don't know. Or maybe its leaking fluid and its low again, who knows. I guess I will find out. I dont know enough about transmissions, and I know the TV cable adjustment is critical on these things. so the shop is probably the best bet.
 
#3 ·
Are you sure the PCM & engine are from a 97? The 97 engine should have a 4L60E behind it which is PCM controlled.If so,are you certain the trans is a 700R4?In order to use a 700R4 w/ a 97 PCM,there would have had to be some reprogramming done to make it work.In order to use a 4L80E,this programming would have to be redone.There would be rewiring(repinning the plugs) required on the swap along with a drive shaft swap(possibly custom made) & crossmember relocation.Adequate space will also need to be verified.More likely than not,you either have an older model PCM & possibly engine or engine mgmt,or,you have a 4L60E.
 
#8 ·
Yes it will bolt to the engine no problem,but,the 4L80E is longer & has a different cross member location which will require a different driveshaft & relocation of the crossmember.IIRC,the front yoke is different also.a reflash will definitely be required becuz all trans parameters have been removed if OP is runnin a 700R4 w/ a 97 system.You will also need the proper harness if it is not still with the vehicle.
 
#17 ·
Like I said earlier,if you can see the bellhsg a 700 will have in big letters,MD8.A 4L60E will have M30.it's important to know exactly what you have becuz the symptoms you describe would be handled totally different on the 2 trans.Like I said bout the 4L80E not bein plug n play,would also apply to a 700 being used with a 97 engine & PCM.Someone woulda went to a lot of trouble to put that trans behind that engine & PCM to make it work.It just don't make sense.
 
#21 ·
I dont know what computer was used... but even if it was for an automatic truck, the wiring could just be left disconnected and it would probably work just fine. I ran an automatic computer in my 74 pinto (which has a 91 mustang engine in it and no VSS) for a while and all it did was pop up some codes for the transmission and vss. It still ran and drove fine. Tho that is a ford obd1 EEC-IV system and not an obd2 gm.
 
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