Forces Posted September 23, 2006 Share Posted September 23, 2006 I am in the middle of installing a TH350 into my 280z. The torque converter spins freely on the input shaft with the trans out of the car. The flex plate is mounted at the crank and spins when I turn the balancer bolt. Here is the problem: When I have the trans mounted to the engine, something is preventing the flexplate from turning at all, its jammed up or something. I have tried putting the trans into different gears, and it still won't budge. I tried turning the crank from the balancer bolt, and I also tried manually turning the flexplate with a flywheel tool that is made for this exact issue....still no luck. Is there a spacer or something that needs to be installed between the engine block and transmission case? I'm pretty much lost. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 23, 2006 Share Posted September 23, 2006 I am in the middle of installing a TH350 into my 280z. The torque converter spins freely on the input shaft with the trans out of the car. The flex plate is mounted at the crank and spins when I turn the balancer bolt. Here is the problem: When I have the trans mounted to the engine, something is preventing the flexplate from turning at all, its jammed up or something. I have tried putting the trans into different gears, and it still won't budge. I tried turning the crank from the balancer bolt, and I also tried manually turning the flexplate with a flywheel tool that is made for this exact issue....still no luck. Is there a spacer or something that needs to be installed between the engine block and transmission case? I'm pretty much lost. Your torque converter is not all the way in the pump, rotate, push, rotate while pushing, it will go in when the dogs on the converter line up with the pump gears. You should have about 1/4 space between the flexplate and the TQ converter when installed properly and you should have to pull the converter up to the flexplate when installing the bolts. If you run it like that it'll wipe out the thrust bearing and ruin the crank. May also ruin the front pump in the trans. Quote Link to comment Share on other sites More sharing options...
jbk240z Posted September 24, 2006 Share Posted September 24, 2006 I agree with Doc 10%. I knew a guy once that had this very problem, no it wasn't me.....honest. OK, so it was me, part of the learning curve. Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted September 24, 2006 Share Posted September 24, 2006 I agree with doc at about that 10% level too... LARRY Quote Link to comment Share on other sites More sharing options...
jbk240z Posted September 24, 2006 Share Posted September 24, 2006 oops, typo, I meant 100% Quote Link to comment Share on other sites More sharing options...
383 240z Posted September 24, 2006 Share Posted September 24, 2006 You should have a MIN of .125" between you flex plate mounting surface and the pads on the TC. Anyless than this you WILL damage your tranny. Also please remember to lube your snout on the TC and the hub that rides in the crank, and be sure to clean out the hub on the crank, old dried grease will harden in there and cause your TC to run of center and can cause a weird hard to track vibration at least, or damage your tc or crankshaft and maybe worse. Keith Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 24, 2006 Share Posted September 24, 2006 I had one do that once, played with it for hours trying to get the converter in. Had a trans building buddy come by and he couldn't get it all the way in. finally, the next day I tried one last time and pop, went right in, bolted up to the block fine, works fine. Quote Link to comment Share on other sites More sharing options...
Corzette Posted September 24, 2006 Share Posted September 24, 2006 Yep! Me too...Push, twist works everytime. Dont forget to put a quart of fluid in the TC before bolting it up.... Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted September 24, 2006 Share Posted September 24, 2006 A fresh trans has a new pump bushing installed like this: Note this pump is set in the case backwards to align the other pump half before final assembly of pump and installation. You can see the new pump bushing behind the gears in the pump. When installing the bushing, the builder should always check to be sure it fits over a converter snout and doesn't have burrs. A new converter and trans with a new bushing can be a fairly snug fit. When installing the converter it will want to hang down, you need to support it so it doesn't harm the seal, and slide it in, turn, slide, etc. all the while trying to hold it centered so it will go all the way in and engage the pump gear tangs shown in the picture. Another thing to note, Sometime a DIY trans builder will install the gears backwards, the tangs are offset towards the rear, if they are installed backwards they becoem offset towards the engine, and then the converter will be completely engage but still not in the proper position. Quote Link to comment Share on other sites More sharing options...
Forces Posted September 25, 2006 Author Share Posted September 25, 2006 I gave it my best....and now I wish that was the problem. I got so fed up with it that I pulled the whole thing down and away from the car to take a look. I wasn't pleased with what I found, and overlooked. The two teeth that the notches from the TC slip onto (you can see in the above pic) were busted off and sitting inside around the input shaft! The end of the converter was butting up against those loose pieces instead of fully engaging. I tried to pull the front cover off the tranny to see if those teeth are connected to the imput shaft or the front pump, but the plate wouldn't budge. Is there a specific puller tool to get it off?? Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted September 25, 2006 Share Posted September 25, 2006 Yeah, You must have tightened the trans up to the motor without having the converter completely engaged like dr. hunt said. It happens.. Get another converter or have yours repaired. There are two holes in the pump, where the pump bolts go through, that are threaded to 3/8-16 threads. You can use an adapter on a slide hammer and thread into those holes and pop the pump out, or there is a pump removal tool you can use that grabs the stator (splined portion that protrudes out of the pump around the input shaft) and uses the input shaft to pull on the pump, or you can do what I do when rebuilding one.. Remove all the pump bolts, remove the pan, and you can see the intermediate clutches through a large drainback passage. Use a flattip or small prybar and put it between the forwardmost steel plate and the intermediate apply piston that is on the rear of the pump, and pry the pump up. It will come out fairly easily. This may help you: http://www.nastyz28.com/forum/showthread.php?t=53671 You can get new pump gears for about $10 from http://www.bulkpart.com but you will need to measure the thickness of your current gears, they vary and you want pump gear clearance to be less than .002". You might also call http://www.bulkpart.com and just buy a completely assembled front pump. A local trans shop may be able to get you one. A reman'd pump for a TH350 is usually $35-50. Really not a bad deal considering, both halves are surfaced, new gears, new bushings, etc. I've gotten to a point if the pump is iffy on a trans, I just install a reman. My time is worth more than $35 to mess with one by the time I surface it, etc. a shop will need to know if it if for a lockup TH350C or a regular non-lockup. Good luck. Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted September 25, 2006 Share Posted September 25, 2006 Also, Make yourself some dowels from 3/8" bolts for install. Get some ~2.5" length bolts and cut off the heads, cut a slot so you can remove them with a flat-tip screwdriver, and thread them into the block, use these to align the trans with the engine. Get the trans flush with the engine block, but before you tighten up the bellhousing bolts, be sure the converter will spin freely. Quote Link to comment Share on other sites More sharing options...
Forces Posted September 25, 2006 Author Share Posted September 25, 2006 Good info, thanks. The torque converter doesn't seem to be damaged. There were notches in the torque converter that slip over, I guess a sort of spline.....it's not really splined, but I don't know what you'd call it. Those appeared to be part of the trans, not the converter.....is that part of the pump, or is it part of the imput? Good idea with the dowls, that would certainly make things easier. Quote Link to comment Share on other sites More sharing options...
Paz8 Posted September 25, 2006 Share Posted September 25, 2006 What about the flex plate, if you pulled up the trans slightly out of alignment it may have been bent and no longer flat, if the pump broke there was a lot of force involved . Quote Link to comment Share on other sites More sharing options...
Forces Posted September 29, 2006 Author Share Posted September 29, 2006 well, the transmission is now repaired and I'm going to take another stab at it either tonight or tomarrow. I don't think the flex plate is bent, it doesn't appear to be at all. Although, if I have the same problem I not gonna be happy, because that'll mean that I have the wrong flex plate. Trouble is, I can't find a different flex plate as a substitute. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted September 29, 2006 Share Posted September 29, 2006 well, the transmission is now repaired and I'm going to take another stab at it either tonight or tomarrow. I don't think the flex plate is bent, it doesn't appear to be at all. Although, if I have the same problem I not gonna be happy, because that'll mean that I have the wrong flex plate. Trouble is, I can't find a different flex plate as a substitute. There are two sizes 156 and 168 tooth, two weights, internal and external (weight welded on). The only thing you could have possibly done is put it on backward. Lip faces out over the crank. In otherwords, the hole in the center of the flexplate has a little lip on one side, it goes towards the trans. I doubt if it's bent unless it's a stocker one, and maybe not even then. Buy a new one if you have to, they are about $30. SFI rated are about $60. If you were here I have several, I'd give you one. I use grease on the seal and shaft of the converter, oil will work fine too, as long as it's lubed. Before stabbing the converter look to see where the pump dogs are and try to install the TC with the corresponding notches aligned right, push on the center of the TC hub with one hand and rotate with the other, should go in fairly easily, but you never know. If not have someone else give it a try as you may not be holding your mouth right. When all the way in you shouldn't be able to fit your fingers inbetween the TC and the front pump. If you can then it's not all the way in. Well at least with my fat fingers anyway. Quote Link to comment Share on other sites More sharing options...
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