MG MGB and MGB GT Tech Talk
Just finished. The lower gears whine, and it's pretty noticeable. I don't know if this will go away, or if the box is bad. It seems to shift smoothly through the gears. Other than the whine, it's nice. Also noticed that when I step on the throttle hard I get some hesitation. My flywheel is lightened significantly now, so perhaps some jetting changes are in order.
Whorst
I get no whine from mine in any gear. There's another thread running right now where Red Line synthetic gear oil was recommended for a hard-shifting transmission: http://www.redlineoil.com/products_gearlubricants.asp?productID=46&subCategoryID=17&categoryID=7.
Here's a tip I got from Glen Towery about the whine:
Overfill the tranny!!! Jack up the right side of the car about 6-8"s and keep filling the tranny until oil starts flowing out. Then go put some miles on it, and the whine will go away the more you drive!
It worked great for me! I had a 3rd gear whine that took about 500 miles to completely go away. I couldn't be more pleased with the final outcome!
Datsun 5-spd gearboxes are as tough as old boots too, so unless the whine is intrusive, I wouldn't worry too much about it.
When I got my L-18 powered Cortina, it had been used as a daily driver for the previous several years on a 150+ mile daily commute. When I did my usual service of any new car that I buy, I pulled the drain bung out, and was horrified to see a small trickle of what looked like melted black rubber pour out of the gearbox.
I filled it with gasoline, let it sit a day, drained it, and filled with fresh oil......two years later it still feels at tight as anything with no funny noises.
mine is far quieter than the stock 4-spd it replaced.
also using Redline MTL.
I should add that mine's not only quieter now than the stock 4-speed, but the gearing is MUCH better as well. I use Mobil1 synthetic gea roil in it, since I never found a difinitive answer as to what the correct lube was.
The people who rebuilt the gearbox suggested 75w90 gear oil. I used Valvoline synthetic. I used just a tad over 2 quarts. It was filled all the way to the top of the filler hole. I believe the manual states 2 1/8 quarts.
After I changed my tranny to a new o/d trans, I had a few weeks of "settling in" with some hard shifting and a few odd noises, but it's all settled down and shifts and sounds just fine now. So, maybe this is normal for some replacement trannies.
Whorst,
Just curious...what was replaced when the tranny was rebuilt? I'm just a few days from testing my Rivergate conversion. Engine goes back in tomorrow. I had the transmission looked at and all the bearings and seals replaced. The gears and synchros were fine. Hopefully, yours will quiet down with some run in time.
-Terry S.
I bought a rebuilt unit from New York Block Exchange. It comes with a 1 year, 12,000 mile warranty. It only whines on deceleration, through the gears is fine. I really like it. The throws are short and tight, and with that aluminum flywheel, it really scoots.
Terry, the Datsun transmission I'm using is one I pulled from a junk-yard 280zx. I don't know how long it had been sitting there, and it oozed pitch-black gear oil when I removed it from the 280. The only service I had done on it was just what you've had done: Seals and bearings. It works like a champ.
Whorst has even more of an upgrade with his new flywheel. His car lost about 60 lbs. in excess iron. Nice.
Did you guys get the speedometer angle ratio adapter with the deluxe kit?? I got the cable, but not the adapter. This is getting irritating.
I got the adapter.. and Will replaced it for a different ratio for me to help get the clock more accurate.
Horst Wrote:
pmittler Wrote:
My tranny came off a running 280zx, it's noisy in all gears but 4th, which is the 1:1 ratio gear, don't know if that means anything. My B has been down all winter, and I've filled it as full as I could get it with Redline, hope it gets rid of the noise.
I only drove the 280 about 10 miles home, but never noticed a noise. Of course, it was in rough shape, so I might have missed it altogether.
I know from this forum that there are folks that would have no qualms about going straight from the salvage yard to the install with the possibility of having to try out more than one Datsun transmission (they are cheap) to find one that works well. Hearty souls who know their way around an engine hoist. For me, it just seemed that doing it once (hopefully) with a rebuilt gearbox was the better option. I'll see if my strategy worked in a few days.
Terry S.
trs Wrote: