my 78 vette got a 3 speed auto box, none of the 3 forward gears are working, reverse does work tho, lol

anyone got some ideas?

how much for a new gearbox? (in the uk)

any tech how to's on taking out the gearbox and re fitting?

cheers

dave

 

Best bet is to find a gear box repair shop in your area, or look for a used one...if not, there are many here, but the shipping cost may be prohibitive.

 

TH400 should be rebuildable even in the UK. Parts are available and shippable, but I would think that you could get them there too. Didn't Rolls Royce use some TH400s in the '70s?

 

Check Ebay, order a kit and a book

 

does a 78 corvette not come with a th350, mine has 3 gears??

how much does a new one cost in the US?

 

Did it just start doing this or has it been broken for a while?

 

78 will have a th350.
If you do decide to buy a new trans, now would be a good time due to the exchange rate.

http://www.bowtieoverdrives.com/index.shtml

would be a good place to start. Try contacting UKPaul or go to the UK forum and send paul81 a pm..he has done this already and says its the best mod he has carried out.

 

Short of checking that there's enough fluid in there, and making sure the shift linkage is working how it should, you'll probably be looking at a full rebuild.
Check those things first - you can move the shift linkage through it's full travel by lying under the car and moving the lever on the side of the box. You'll need to do that whilst the engine's running, so for christ's sake have someone in the driver's seat with their foot squarely on the brake, or you might end up running yourself over, quite an impressive feat in itself, i guess


If you're sure the shift lever's moving the lever on the side of the box, squarely into all 6 positions, and there's fluid in there, then it begins to look like an internal problem. Since it's quite a big job in terms of time (but not necessarily in terms of difficulty), it's just not worth tearing it down to just repair whatever thing, or things, have gone belly up inside it. The master rebuild kits aren't expensive so it's just as well to do all the seals and clutches in one go.
How handy are you with a spanner? And how much time and space have you got? There are plenty of books on rebuilding the TH350, I bought the US Haynes one when I did mine.
If you don't fancy doing it yourself then just getting the box out, ready to farm the job out, isn't that bad either.

Any half decent UK auto trans place should know their way round a th350, they have been used over here in some cars, I believe. Although shop around, 'cos some of them seem to like to keep us all believing that there's some kind of witchcraft going on inside these boxes and that they can charge you up the a$$ for fixing them! Either way I expect you'll be looking in the few-hundred-quid region for a rebuild, depending on if you supply the kit yourself or not.

Good luck!

 

cheers for info guys, i will get garage to check linkages tomorrow, see wot comes of that first

cheers

 

as someone mentioned, check the transmission fluid level...you maybe down on fluid, thus your problems.

 

Sorry, I misread your post. I thought it said a '73 instead of a '78. That would be a TH350 instead of a TH400. I would think that rebuild kits should still be available there, but could be wrong.

 

http://store.summitracing.com/egnsea...nresults=false

 

While 78 came w/ a TH350, both the TH350 & TH400 were used in Vettes, so if getting the TH350 done is a problem there the TH400 is another option. Jag used the the TH400 in some cars like XJS.

 

Can you not contact GM UK for a source of parts or a rebuilt unit?

http://www.chevrolet.co.uk/about-us/...-overview.html

 

Dave,
are you in the CCCUK? I did a (lengthy!) article on swapping out a stock trans for an overdrive unit in the club mag a couple of years ago that might be worth reading (if you've got the time ). I might still have a copy somewhere if you want? In the worse case, getting the trans in/out is a piece of cake, it's a doddle compared to something like swapping an intake manifold. The most difficult part of the whole exercise, I found, was getting the car up high enough to slide it out from under it.
If you do find that yours is knackered then I'd highly (very) recommend checking out a 200-4r from Bowtie Overdrives. As Jotto (hi ) said, the exchange rate is good, plus their shipping charges were a lot less than I was expecting, very reasonable. If you do take that route then you'll be wondering how the heck you ever drove it without enough gears when you've discovered the joys of overdrive on a motorway (staying with traffic in the fast lane while the engine is just burbling along & the fuel gauge isn't sinking is a revelation). I wouldn't be exagerrating to say that the savings in fuel my OD trans has given me have gone a long way towards recouping the initial cost of it.
If lack of cash is a problem then you can get yours repaired here. I don't know where you are, but if you're in the Norfolk area then Corvette Kingdom gave me the number of a specialist they use who were very helpful with my Th350 problems. Or they (or another Vette specialist) may have a used box for sale?
Good luck, hope it's something simple.

Hey Theo, how's it going? You can't go using words like "spanner" on here you know!

 

Gotta love the British vocabulary....

 

Sometimes the differences in our common language can really throw a spanner in the works

 

thanks for info guys, checked fluid and linkages today all fine, so must be somthing internal, so the box is coming off!

looked at recon prices, there all round £1100 + including uk vat

corvette parts place in uk, have a new th350 in stock - £893 including uk vat
also put new torque convertor in £117.50 including vat, local garage to fit, job done!

what should i do with old box and torque convertor??

cheers

dave

ps - ukpaul - yeah asked the same questions on cccuk, lol, how much time to fit new box??, how much time to take old one off?? cheers

dave

 

Dave,
Woah! Stop!!!! For the money you're talking about for a replacement you can get an overdrive trans from BTO. Mine cost me, as I remember, about £1300. That included freight & then an additional new x-member that you won't need (as it's pre '80) & freight charges for it (ouch!). This was when the exchange rate was nowhere near as favorable as it is now. I highly recommend that you look at this:
http://700r4.com/sitemap.shtml
Sorry, haven't looked at the CCCUK site this week.
I reckon you could pull a trans & fit a replacement in a leisurely day. There's some nice instuctions on doing it on the website above. However, that doesn't include such things as finding clapped out driveshaft UJ's, broken engine mounts, etc. To fit an overdrive trans I reckon I could do it in a weekend, including modifying the carb for the TVMade EZ kit, fitting the new logo on the shifter plate, etc. That's assuming nothing else needs doing while under there eg UJ's. The instructions supplied are very comprehensive, apart from one small detail that can really screw up your day (I can give you plenty of help if you go the OD route).
(£893 + £117) * 2 = a lot more $'s than a 200-4r + 2200rpm stall locking torque converter + all the little extra do-dads cost me to do the OD upgrade. Give it a lot of thought before jumping for another Th350

 

thanks for the info mate, iam happy with 350 route, less hassle geting it from the uk, etc, also im not going to be using the vette for long distance's etc, short local runs, also i like the idea of keeping it the same, thats the way they made in 78, thats the way its going to stay! lol

cheers, thanks for your input

dave