tranny failure- 2005 pontiac montana 3.5 sv6

sunfire2door

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ok guys my friends 2005 Pontiac Montana 3.5 sv6 with 130,000 kms has a tranny failure. he said that he was driving forward and Bam the car shook so violently... Than went to the library the car wouldnt move than, it only drives in D1 and D2, D3 and D both dont work he said there were no warning lights and bam it just went. is their a common fail point with these tranny's in the Montana's as in Toronto theirs so many of them on the road. help please???
 
Haven't gotten into the internals of the Montana transmission but had several Nissan with same issue. It was a governor gear that went out. The governor great is usually belt driven and the belt will wear out. Usually easy to change through an access door on transmission.
 
did you check the transmission fluid level? did you ever change the filter and fluid?
 
did you check the transmission fluid level? did you ever change the filter and fluid?

well he went through some of his maintenance history and one of them noted that he had burned tranny fluid at 100,000 kms and now it has 130,000 kms.he usually checks his tranny fluid once or twice a year, so it was probably low and the tranny probably overheated due to the lack of lubrication. he literally bought the tranny fluid and filter on sunday and was going to change the fluid on saturday, and told me that the tranny case had a hole at the side and he can see metal shavings on his tires etc... and he saw dripping fluid. so at this point he either needs a rebuild or a new one altogether. what do you suggest? its a lady driven van so no abuse to the tranny what so ever. is this common on the 05-09 montanas?
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He has to find a rebuilt one or a junkyard used one that is guaranteed to work. This is not common most likely due to some lack of maintenance or abuse in the past, is he the original owner? Being lady driven has no bearing on the problem. If she jumps in the vehicle when it's cold and drives off quickly before it warms up, or she gets stuck in snow and constantly lets the tire spin even though the vehicle isnt moving are examples of unintentional abuse.
 
He has to find a rebuilt one or a junkyard used one that is guaranteed to work. This is not common most likely due to some lack of maintenance or abuse in the past, is he the original owner? Being lady driven has no bearing on the problem. If she jumps in the vehicle when it's cold and drives off quickly before it warms up, or she gets stuck in snow and constantly lets the tire spin even though the vehicle isnt moving are examples of unintentional abuse.


Hi, So im the current owner of this van (Thanks for creating this thread Sunfire). I am not the original owner, we are the second owner. However you are right, the driver of the vehicle is one who lets the tire spin in snow... However we always let the Vehicle warm up before driving. The car was due for the Transmission oil to be changed. I also remember the Wheel Bearing was making some noise (could this be related?). Otherwise today The gears that work is only Reverse, and D1 all other gears will not work (D, D3, D2). A friend thought the problem could be a "Forward Sprag Assembly", could this be a possibility? Thanks for the help!
 
Can't speak about the tranny but I do know the bad wheel bearing and tranny are not related.You can call around to tranny shops and get opinions and estimates that will help you educate yourself. It is ashame about trannys it seems like its all or nothing. I would make sure that the transmission lines are both ok and not spewing fluid.
 
Can't speak about the tranny but I do know the bad wheel bearing and tranny are not related.You can call around to tranny shops and get opinions and estimates that will help you educate yourself. It is ashame about trannys it seems like its all or nothing. I would make sure that the transmission lines are both ok and not spewing fluid.

Thanks for the response there was some transmission fluid leaking... However its at the dealership now... Ill post and update, when the dealership checks the vehicle!
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he took it to the dealership and they said that he needs a new transmission or a rebuild, but i advised him just to find a used one as it would be more cheap to find and replace. as with a rebuilt you'd probably need parts, more labour etc...
 
It would also be cheaper if your local tranny shop did the work. If your going to keep the van for a long time (maybe more than a couple of years) I would get it rebuilt ,it may cost more but you have a warranty and it may last longer. Who knows ? I know around me most dealerships contract work through the tranny shops,then add there labor and markup......
 
well good news he got a used tranny from a local shop. the tranny is from a 2008 Montana with 65,000 kms! as of right now I don't know where he is going to get it install the used tranny, hopefully MontanaG8 can keep us updated.
 
glad to here. sounds like there on the right track.
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Update: Transmission got fixed, works like new... Managed to save A LOT than what the dealership had offered to fix for. However wheel bearing made real bad noise so its still in the shop. But all in all the transmission is fixed :) The cause was poor maintenance (Transmission Oil was never changed, Assumed the previous owner had it changed, guess not)
 
glad it worked out for you
 
Update: Transmission got fixed, works like new... Managed to save A LOT than what the dealership had offered to fix for. However wheel bearing made real bad noise so its still in the shop. But all in all the transmission is fixed :) The cause was poor maintenance (Transmission Oil was never changed, Assumed the previous owner had it changed, guess not)

glad your tranny is fixed bro!! your lucky the shop isn't charging you for the labour on the wheel bearing. have you ever had your coolant changed? hopefully this tranny will last you a while!
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Update: Transmission got fixed, works like new... Managed to save A LOT than what the dealership had offered to fix for. ... The cause was poor maintenance (Transmission Oil was never changed, Assumed the previous owner had it changed, guess not)

I have a 2009 Montana SV6 and my local transmission guy says that all GM transmissions run hot. Even if not towing anything, they run "too hot" during summer hot temp blistering days.

With this warning in mind, I installed an aux ATF cooler for attached 5,000 lbs trailer in my mini-van. No worries, I never pull any trailers over 2,500 lbs. And, I might pull a small utility trailer 3 times a year - for local dump runs. Since installing the Hayden or slightly better Tru-Cool aux ATF LPD (Low Pressure Drop) design cooler (re: http://www.bulkpart.com/2/product/hayden-transaver/OC-1678.html ), my van's tranny fluid looks brand new. Any, my van run cooler as well.

As a proactive improvement above factory minimum build, do install aux ATF cooler for attached 5,000 lbs trailer as well. In the long run, its low cost for this cooling improvement.

Works for my GM mini-van...
 
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