darom Posted February 19, 2009 Share Posted February 19, 2009 Guys, I need your expertise on whether or not I need to replace this part. My friend and I took apart a junker's 5-speed (1979 280xz with 310k miles) to find that overall it looked very clean inside, all bearings and synchros looked good for its age. The only problem is the main drive gear with its pitted teeth. I was ready to order the bearings/synchros rebuilt kit, but if there is way to save money, I am all for it Can my current 4-speed 1976 tranny's main drive gear be interchanged with the 5-speed one? This 4-speed has 2nd and 3rd popping out gear problems (while driving the 2nd and 3rd pop back into neutral). I can't find anybody online who sells _just_ the main drive gear. Maybe someone has a used one he/she can sell me? Before I take the tranny to the shop locally, can someone have a look at a few pictures and give me their professional/hobbyist advice? Here is the link to the album: http://s24.photobucket.com/albums/c1/darom/ The areas of concern are here: http://i24.photobucket.com/albums/c1/darom/IMGP0522.jpg http://i24.photobucket.com/albums/c1/darom/IMGP0521.jpg http://i24.photobucket.com/albums/c1/darom/IMGP0512.jpg I appreciate your help. Thanks. Den '76 280z - work in progress Quote Link to comment Share on other sites More sharing options...
darom Posted February 19, 2009 Author Share Posted February 19, 2009 I have no clue how to introduce paragraphs to my above post. Sorry about its messed up look. Got it - firefox is not working well with this bulletin board software. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted February 19, 2009 Share Posted February 19, 2009 Honestly, just look for another trans. They can be had for MUCH cheaper than the labor and parts cost of repairing one. As long as the ratios are the same, the four and five speed gears should be the same...asides from the 5th gear parts. However, if chunks floated around the trans, you don't really know which bearings may also be bad, and what other parts might be worn. Quote Link to comment Share on other sites More sharing options...
darom Posted February 19, 2009 Author Share Posted February 19, 2009 I wish it was that easy. I already paid some $$ for this tranny + my time removing, cleaning and disassembling it. Quote Link to comment Share on other sites More sharing options...
rejracer Posted February 25, 2009 Share Posted February 25, 2009 "They can be had for MUCH cheaper than the labor and parts cost of repairing one." -Very true! I just purchased a JY trans for 80 usd. But don't know what the internals are like. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted February 25, 2009 Share Posted February 25, 2009 I've a FS5W71B that has had the starter bulge cut and re-welded around the bell further for a Previous owners unfinished project. No use to me but the gears seem to change fine and the shaft turns easily by hand, I think postage from NZ to CA for the whole gearbox would be pretty prohibitive tho. Posting a 200x200x150 mm parcel weighing 3.5 Kg came to 32 USD approx when I was pricing postage for a Carbie I had listed on ebay. Thats surface mail 10 day transit. Since it's bellhousing has been altered and I've no need for the Gbox since I'm not going L series again and already have a M76 falcon box for the swap, I'm willing to pull it apart and junk the housing for the aluminium value, and sell the innards. $20 USD plus whatever postage comes if not to extorbinate to sound alright? If you weigh up the 5sp internal bits you want from yours and measure the length I can plug the size and weights into the post shops online calculator for a postage quote if you like. Quote Link to comment Share on other sites More sharing options...
darom Posted February 26, 2009 Author Share Posted February 26, 2009 kiwi, thanks for the offer. I might consider it - I am taking the tranny to a mechanic this week who might have a few used input shaft gear assemblies laying around. If he doesn't have it, I will be contacting you. I am attaching the picture of it. Thanks! Den Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted February 28, 2009 Share Posted February 28, 2009 What condition is the countershaft gear in? It is in constant contact with the first motion shaft so it seems logical that there's be damged on those teeth too. Quote Link to comment Share on other sites More sharing options...
darom Posted March 1, 2009 Author Share Posted March 1, 2009 Countershaft gear appeared to be badly pitted as well. Upon removal of the gear we saw more damage then from the previous overall quick inspection the day before. The mechanic who helped me said that if left alone the tranny would have made loud 'supercharged' noises I decided to have it rebuilt with new bearings/synchros parts. I am keeping the car (so much $$ invested into it that it is beyond the point of no-return) and would like to have it done right the first time. The two gear assemblies will be replaced with good used parts from a different tranny. Thank you guys for your help. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted March 2, 2009 Share Posted March 2, 2009 Try Zbarn in TN. He has been known to supply me with tranny internals before. Quote Link to comment Share on other sites More sharing options...
darom Posted March 2, 2009 Author Share Posted March 2, 2009 cygnusx1, thanks for the reference! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.