How to TH350/TH400/200r4/powerglide your V6 vn-vy.

[delcowizzid]

How to TH350/TH400/200r4/powerglide your V6 vn-vy.

so people are allways asking how to upgrade to a decient auto gearbag in there higher powered v6 commodores heres the cheapest solution for anyone who has access to a welder and grinder and a few tools or has a shop who can do the extra mods required.this will even suit series 1 vn manual enguine to auto swap and that is what the pictures are of.you could also use this to upgrade to a serious manual box as well.

First the adaptor plate to convert the buick and emotec to chev bolt pattern it also comes with an adaptor that fits in the crank of series 2 engines to centre an unmodified chev convertor.its extremly cheap to say the least http://www.speedwaymotors.com/Chevy-4-a ... ,3280.html theres a PDF of fitting instructions on that page too but to fit on the v6 there is a few bolts etc that dont fit like the instructions.

so now that we have the plate we can bolt it too the engine.you will want to use allen key headed bolts to get clearance and save removing any unnessicary alloy from your bellhousing.

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at this point ive allready welded on the bolts to hold on the gearbox the top middle left bolt has to be a bolt with no head at all and just plug welded into the plate the one to the left of that bolt ive welded on a nut just cause i could.the bottom left is a bolt with 1 3rd of its head cut off and locks itself in place against the block saves making a spanner to fit in there to hold it.its upto you on how many bolts you weld on after this you could do all but the bottom righthand one if you want.you also need to weld on the 2 dowels to align the bellhosuing onto the plate we just used a peice of stainless towel rail we had lieing round as chev engine dowels were not able to be bought from any shops here in town and no one had any spare old used ones.
you will also see that the bottom right bolt that holds the plate to the block is a tapered head allen key bolt and the one supplied does not fit right through the block and will need to be a longer one with a nut on the back our block doesnt have a thread like the chev 60* v6.it also needs part of the bolt head drilled out to fit the lower bellhousing bolt through once the plate is bolted on for the last time.you also need to cuntersink part of the block wing for the bolt head to sit flush on the plate.i used a tapered grinding stone in a drill to do this and took very little effort. the one in the middle of this pic

now for a flexplate for series 2 you can use the original v6 plate for series 1 manual vn we need to make a flexplate. it just so happens that the crank is the same as chev v8 with the exception that 1 bolt hole is half a hole out and needs slotted.

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now that the flexplate bolts onto the v6 crank you need to take the ring gear that the starter ingauges on off an old v6 flex plate this is easiest done in a lathe while you are at it cut the v8 plate down so the ring gear fits it again use a lathe to do this.now weld on the ring gear.

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you can see the slotted bolt hole and the 3 convertor bolt holes that just fit on the pads.now get the flexplate mirror balanced to your old flywheel or flexplate.you can see the heat marks on the lower right where we had to weld a lump of round steel bar to the plate to match the balance ill get a pic of the other side tomorrow.

now the box we are using a duel bolt pattern T350 its both chev and oldsmobile or something it came with a ute we bought and has done 1 lap round the block behind a 327 after being rebuilt before the engine died a horrible death LOL.

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we could of cut off the 2 top mount holes but retained them for all the strength we can get as this will be launched off a transbrake at decient revs.you can see that we had to clearance it for the top 2 allen key bolts that hold on the plate right beside these 2 lugs next picture will show you again the clearancing.also beside the bottom right bolt hole needs a little flapper disk action to clearance another bolt head.

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this pic also shows our modified 3500rpm chev highstall convertor which fits perfect in the crank but needed new bolt mounts to attach it to the smaller flex plate its aa9" or 9.5" jobby so is about the same size as a stock v6 convertor.for the people doing series 2 you will either use the supplied adaptor to fit a convertor with the extra tabs attached .or you can get the v6 convertor changed to chev splines like we are doing to another V6 with a T400 behind it in chrrs vr turbo then it all just bolts onto all the stock flexplate and fits the crank without needing the adaptor.
youll need to make a gearbox crossmember to suit here is the one we made to fit VB commi floorpan total cost less than $10

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and the driveshaft needs to be longer so cut off the ends of the old shaft carefully with a 1mm cutoff wheel and slide them up a new length of pipe here you see the middle and front yokes pressed into a peice of pipe that we salvaged from the rear half of a vn driveshaft we had lying round.its not welded together yet as it needs to be put in a lathe and the middle yoke checked for straightness to the shaft and welded on.

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now bolt it all in and fit your favorite shifter we chose a quicksilver ratchet shifter for no missed changes

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any questions feel free to ask im not on as much as i used to be but ill try to answer most questions

[VL400]

Champion, will be a very handy guide

[Holden202T]

nice write up delcowizzid!

[delcowizzid]

shes a bit rough and ready but it puts pictures to the pdf and gives people an idea on how it all goes together

[Holden202T]

i assume this is in the turbo v6 vb commodore ?

[delcowizzid]

sure is flex plate and driveshaft get balanced tomorrow and then we can bolt it together and try it out