altghough i have built many cars i'm about to attempt my first rebuild of a th350....i've always had someone else do it. i've ordered a manual off ebay from ATSG to guide me through it , but what kit do i get? checking ebay , napa and O'Reilly i see that there are different completeness of kits with different types of clutch plates and different prices. different brands , some have bushings some do not, etc what kit should i use? i'm a automatic tranny newbie other than changing front/rear seals , shift kits and filters
Im no pro and have not attempted this myself but i would guess that it depends on how much horsepower and torque your going to run thru it. When i had my 350 built the guy put an extra band in each set. I think stock it had 4 and i have 5. Also ive heard the waffle disks are supposed to be really good but costly. Rebuilding a tranny can run you alot if you get into high hp. I guess im not much help to your question though. Probaly just need new disks, gaskets and a shift kit.
For a first timer I recommend geting the Ron Sessions(sp) book from H.P. I don't buy anything until after tear down, then you know what you need, I buy my stuff from the local Napa guys.
I agree, teardown and inpsect, plan level of build and buy appropriate kit. I bought a few kits from Northern Auto in the past but its been about 5yrs since I really checked pricing from different places, at the time it was the best kit for the $. http://www.northernautoparts.com/ProductModelDetail.cfm?ProductModelId=1845
thanks for the info. i'm looking for a basically stock rebuild , it will have a mild 283 in front of it that kit from Northern says it has the "popular" bushings....does that mean there are some bushings not included? do all bushings need to be replaced?
Hey a man after my own heart, 283+TH350. I don't like to buy kits, I buy what I need you might be surprized at how little you need, maybe only gaskets and seals/sealing rings. I delayed my 1-2 shift point to help the little 283 out. 2-3 seemed to be ok.
thanks , i will tear it down after i get the book. i believe it to be working fine when pulled , so it may not need much. just want to be safe because i'm lazy and i hate doing things twice
Sessions does a good job of explaining endplay, and how it translates to longevity, its the most important measurement in my mind.
https://www.wittrans.com/Default.aspx? they have a master kit with steels for about $80.00. I've used their kits for years with no problems.
thanks , i just ordered the Ron Sessions book too checking other threads here on the Hamb and googling "th350 rebuild" , i see that you need a special tool for the rear clutch springs. i found it online for $40 , but i'm cheap and have the stuff to make one. does anyone have this tool and give me some of the key dimensions? thanks in advance. it would give me something to do this afternoon i use to have them rebuilt from a guy in his home shop that charged $275 with a rebuilt converter , but now has gone big time he has a big fancy building to pay for and now gets $550 for a basic rebuild. i have no problem with a guy making money , but i might as well make that money myself
I have been using this one for 30+ years, one size fits all. You need more than the one you pictured to take the other clutch packs apart. You could make what you need and use a drill press as the compressing device if you were so inclined.
TH350's are prone to bushing wear, so replace ALL of them, and use an EXTRA bushing in the sun gear to stabilize it. You can swap to thinner pistons to get more plates/steels in the clutch packs, or cut your existing ones down. Get a hardened sprag race, it's the weakest part of a TH350. Use a quality shift kit, such as TransGo. Over on HotRodders.Com, in the transmission/rear end forum, is a sticky by "jakeshoe" on what to do to a TH350 (there's also one on the TH400). The Jan 91 Hot Rod Mag has a good article on beefing the TH350 also. As already mentioned, the Ron Sessions book is a good one, but it can be a little confusing as it deals with the TH 250, 250C, 350, 350C, and 375B. With your small engine, you may want a little looser converter; a remanned one originally made for a Vega will help quite a bit in a street car. Butch/56sedandelivery.
A thought on the clutch plates: I have done many trans, but the longest-lived ones were always Mercedes trans. Possible reason: they have really thick clutch plates (5mm or so). Now we all know that you can only put so much heat into a clutch plate before it warps, and the thicker the plate, the more heat before it warps. Just a thought. And as for the rear clutch compressor - I used a steel table with a threaded hole in it. Set the trans on end, and with a bit of threaded and a bit of angle, I compressed the clutch pack. Real cheap. Cosmo
I did my first one using this book. Went surprisingly smooth till I found out I needed that clutch pack tool. Went to the scrap metal pile and built one. Worked great. Be careful tightening things back up, it's easy to strip those screws in the aluminum housing.
The tool you showed... You can get the spread dimensions on teh lower piece when you pull the tranny apart. What I did for the upper portion... bought a 2 ft piece of threaded rod from hardware store. Tapped a hole in a 1/2" by 1" bar about 1.5' long - long enough to span the top of the tranny. Bolted the long bar to the tranny and threaded it down. Hope that made sense. I bought the book, but better than that - there is a video I got off of EBAY. Excellent, shows how to inspect, remove bushings, etc. The book has the bushing dimensions, I made a removal and install tool on my lathe that took care of 8 of them. Get a master rebuild kit, it will have more parts than a regular kit.
All above sounds like good advice. I would like to add one more thing. I preferred the NAPA kit and TransGo valve body springs+ instructions. If you get a shift kit for the street, most will have a drill bit that you use to open or enlarge a couple holes. I recommend that you use the "RV" settings for shift firmness. Often if you use the larger bit to make a larger passage hole, you get too rough a "race" shift for long life on the street. The middle "RV" setting usually gives a good strong clutch engagement for street and hotrodding without the really hard hitting "RACE" shifts that shorten the life of a trans. DON'T FORGET A HARDENED SPRAG. The stock ones split apart too easily with hard use. Just my 2 cents.
...yes, the hardened intermediate sprag outer race is damn good insurance. The modified direct drum and a sprag from a 400 trans is really the way to go but costs a few bucks. Don't just try to use a bunch of extra plates in the clutch packs! Set them up like Session's book says and you won't have any problem.
The KD spring compressor shown in coupster's photo is what I have, it works on a lot of different transmissions. TH350s wear out lots of parts....pumps, drums, input shafts, etc. Careful inspection of every part is vital. A stock rebuild with a mild shift kit is fine for most applications--assuming you're starting with a core that was behind a 350, not a six or 307 (they are skimpy on the clutch packs). I do the freebie homebrew shift kit (restrict the accumulators, shim the pressure regulator, enlarge the clutch feed holes), but transgo is the way to go if you buy a kit.
one thing about some of the bushing that are sold is some have more clearance than they should have. i have made multiple tools to compress clutch packs but you need to invest in a quality tool to install the internal seals. using a feeler gauge works but you risk tearing the seals. i have seen homemade stall converters and they work for "limited time" because all that excess pressure will make them "grow" or "balloon" and fail unless they are reinforced.
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